Breeding – A beginners guide to inbreeding and line breeding

Animal Care College – caring for people caring for animals


My thanks to Sue Bowling for allowing me to quote extensively from her article

First and foremost I should emphasise that line breeding is the cornerstone of selective breeding. Selective breeding has given us cows that give the maximum amount of milk, sheep that give the maximum amount of wool, chickens that lay eggs almost every day and the most beautiful dogs in the world. There is nothing wrong with line breeding but it is like using a satellite navigation device – if it is not used intelligently you land up in Richmond, North Yorkshire when you intended to go to Richmond in London! If you are to use line breeding intelligently you have to know the basics. I hope that this short article will help.

What are inbreeding and line breeding, and what effect do they have?

In genetic terminology, inbreeding is the mating of two animals who are related to each other. In its opposite, out crossing, the two parents are totally unrelated. Since all pure breeds of animal (including humans) trace back to a relatively limited number of foundation ancestors, all pure breeding is, by this definition, inbreeding though the term is not generally used to refer to matings where a common ancestor does not occur within a five-generation pedigree.

Breeders of purebred livestock have introduced the term ‘line breeding’, to cover the milder forms of inbreeding. Exactly what the difference is between line breeding and inbreeding tends to be defined differently for each species for there is no ‘formal’ definition. Inbreeding at its closest applies to what would be considered incest in human beings – parent to offspring or a mating between full siblings. However, uncle-niece, aunt-nephew, half sibling matings, and first cousin matings are called inbreeding by some people and line breeding by others. Under normal circumstances if this was the only example of close breeding in a five-generation pedigree what is called the ‘inbreeding coefficient’, expressed as a percentage, would be so low as not to be significant. But three things need to be taken into account. The closer this relationship is to the first generation of the pedigree, the more often it occurs and the relationships of the other sires and dams in the pedigree all result in an increased percentage.

What does inbreeding (in the genetic sense) do? Basically, it increases the probability that the two copies of any given gene will be identical and derived from the same ancestor. The higher the inbreeding coefficient the more likely this is to happen. The technical term is ‘homozygous’ for that gene. The ‘heterozygous’ animal has some differences in the two copies of the gene. Remember that each animal (or plant, for that matter) has two copies of any given gene (two alleles at each locus, if you want to get technical), one derived from the father and one from the mother. If the father and mother are related, there is a chance that the two genes in the offspring are both identical copies contributed by the common ancestor.

This is neither good nor bad in itself – but consider, for instance, the gene for PRA (Progressive Retinal Atrophy), which causes progressive blindness. Carriers have normal vision, but statistically, if one is mated to another carrier it is likely that one in four of the puppies will have PRA and go blind. Inbreeding will increase both the number of affected dogs (1 in 4) and the number of genetically normal dogs (3 in 4) so inbreeding can thus bring these undesirable recessive genes to the surface, where they could be removed from the breeding pool – you do not breed from the dogs which go blind – although a proportion of other dogs in the litter will be carriers.This will only matter if they are mated to another carrier, of course, but it demonstrates the complexity of the problems

Unfortunately, it is still much more complicated for we cannot breed animals based on a single gene – the genes come as just two packages: one in the sperm and one in the egg. So you may be able to eliminate one undesirable pair but the very fact that the animals will be becoming increasingly homozygous (which may quickly improve some characteristics) is also likely to bring other undesirable combinations to the surface.

Sewell Wright developed what is called the ‘inbreeding coefficient’ in the 1920s. This is related to the probability that both copies of any given gene are derived from the same ancestor. A total outcross (in dogs, probably a first-generation cross between two purebreds of different, unrelated breeds would be the best approximation) would have an inbreeding coefficient of 0. As we have seen, they would still have common ancestors many generation back so would still be homozygous for somegenes shared by all dogs so even though the inbreeding coefficient = 0 even matings between unrelated pairs can still throw up genetic disease.

An inbreeding coefficient of 100% is rare in mammals and would result if the only matings practiced over many generations were between full brother and full sister. A mating between a brother and sister from unrelated parents would result in an inbreeding coefficient of 50%. A mother/son (or vice versa) or father/daughter (or vice versa) mating would result in a breeding coefficient of 25% assuming that there were no other related matings in the preceding generations. A cousin-to-cousin mating actually gives a relatively low percentage (6.25) but other related matings would affect this figure – perhaps substantially. However, Dr Malcolm Willis, one of the most experienced geneticists in the world of dogs, has said that the average inbreeding coefficient in pedigree dogs registered with the Kennel Club is actually only between 4 and 5% but, of course, the long term effect of many generations of a breed on the same register will mean that today’s dogs do have a higher chance of passing on deleterious genes simply because, as explained at the beginning of this article, there were relatively limited number of foundation ancestors.

As a general rule, very close inbreeding in domestic animals cannot be maintained for many generations because it generally results in loss of fertility – apart from any other genetic disease which may become apparent. .

To ensure genetic health breeders need to select pairs in such a way that the inbreeding coefficient of the offspring is kept as low as possible commensurate with the adherence of stock to the breed standard.One way of doing this is to use the method often adopted in other countries: that is breed from animals which ‘look’ the same (heterozygous) as distinct from what we tend to do in the UK which is to breed from animals which are genetically similar (homozygous).

Another key is to constantly move away from families known for possessing deleterious genes – a method practiced by knowledgeable dog breeders for generations.

You can download a programme from the Internet called GENEs which was written by Dr Robert Lacy which will enable you to calculate the inbreeding coefficient of any mating (assuming you have the full five generation pedigree) quite easily. The programme is free but has some restrictions. Go to to download it.

Genetics is an immensely complex subject and this is but a simplistic introduction. Much more can be found at including the formula for working out inbreeding coefficients.

851 Comments on “Breeding – A beginners guide to inbreeding and line breeding”

  1. Robyn Says:

    I am thinking about putting my bitch to a dog which both have same mother but different fathers.

    or my bitch & the dog have mothers that are litter sisters

    what is your thouhts/

    • davidcavill Says:

      I would need much more information before I could comment. My initial reaction is ‘no’ but if you are an experienced breeder, are trying to selectively breed against an unwanted characteristic then is might be feasible. Dachshunds have a relatively broad genetic base so you should not find yourself in the position of mating so closely under normal circumstances

      • froggy21doggy Says:

        what about uncle to niece

      • davidcavill Says:

        What is the breed? Are the dogs sound and healthy? Are they listed on Breed Watch? It is quite close and I would not unless you are really experienced

      • froggy21doggy Says:

        yes the dogs are (sound and healthy)…..they are show dogs the grand parents are grand champs purple ribbon on both mom and dad side

      • froggy21doggy Says:

        thanks keep u in formed

      • stephen Says:

        I have one male and one female Italian greyhound that has both different parent but share same grand mother and different grand father. Can these two mate without a problem?
        Thank you.

      • davidcavill Says:

        Other things being equal there should not be a problem –

      • bella Says:

        Sire: Kenynten Prospect
        Dam: Leo Aureum

        Any puppies from this mating would have a coefficient value of
        The annual average inbreeding coefficient for the Dobermann is
        this is my result for my dogs one great grandfather is the others great great grandfather .Meaning I think prospect mum is Leo great aunt is that a problem when mating ?All health checks done and both dogs vid clear and dcm tested clear which can change yearly so they are tested yearly .

      • davidcavill Says:

        Thnaks should work

      • Forget The Brand Name Says:

        So I have trying to find answers for this
        I have male A and female A

        A and A had male b and female b
        Male b mates with a female say z
        Can puppies from female z and make b be mates with female b?

      • davidcavill Says:

        I would have to know much more about the breed before commenting

    • I read somewhere that it’s ok to breed fathers-daughters, but you should never breed mothers-sons. If that’s true, why?

    • Sally krotzer Says:

      Love my Carin terrier
      More fun then any dog I owned
      I want to breed her
      She is a red wheaten
      If I had a black male
      What colors would I get?
      Is their a color chart?
      I know their color change
      But what color would they be when their born?
      Thank you

  2. John Wilders Says:

    This is great a good explanation on inbreeding that is understandable to the average “moderately” intelligent (where genetics are concerned) dog breeder. It’s long past time when we should take out the emotion and the anthropomorphism from the subject of close breeding s. We need to find the balance between the health of our breeds and the maintenance of breed type and heritage..

  3. stacey Says:

    i am thinking of breeding a father yorkie to his daughter. No health issues have been noted in the father. Is this ok?

    • Bob Myers Says:

      We have Akc shelties. Our female is half sister to our friends male. Our female has had pups from an unrelated male. Can we breed her female pup to our friends male – uncle to niece?

      • davidcavill Says:

        Yes, If both are healthy that is fine – once! You should not repeat it generation following generation with out an out cross every 3rd generation

  4. davidcavill Says:

    I would not. Apart from the fact that the Kennel Club will not register the puppies it is a relationship to be avoided simply because it significantly reduces the gene pool and if there are any genetic defects (even if they are not visible in father daughter) they may still be lurking and this may bring them out. At There are plenty of good Yorkshire Terrier stud thoughts about. I would use one that was at least two generations away and if you can find a suitable outcross that would be good

    • Ken Says:

      Concerning line breeding. I have a male and female from the same mother but different fathers. The male was from his mothers first litter. The female is from the mothers 2nd litter, 3yrs later. Can I breed these two safely? What are the dangers?

      • davidcavill Says:

        It all depends – on the breed, how sound they are and what your objectives are. If you are not experienced and want to breed always go for a dog or bitch that ‘look’ similar but has a few common ancestors as possible.

    • Ken Says:

      Are pups from the first and second litter with different fathers still considered direct siblings? And therefore a bad choice to breed?

      • davidcavill Says:

        They are half siblings. I would avoid breeding them closely. Use and outcross – assuming they are healthy and clear of any genetic defect

    • Alisha Says:

      I just got a female yorkie that has already been breed with a different breed and now I want to breed her with my yorkie… I guess what I’m trying to ask is does the breed of the first litter stick around and affect the next litter??

    • Jae Says:

      I am thinking of breeding my male who’s mother is the females grandmother. Is that too close?

  5. stacey Says:

    thank you for the input. one last question though. Is it ok to breed a male to a female that have different mothers, but the same father

  6. davidcavill Says:

    In general, the principal of line breeding should be not to use relatives of the immediate previous generation at all. What you have to remember is that the closer the relationship the more likely problems will occur(this is not necessarily the case but statistically the chances are significantly greater closer the mating – and greater still if this practice is continued over several generations). So the sensible thing is to stay as far away from the immediate relatives as possible. My advice is to try and have at least two generations separating any given mating and that this should only be done twice in every three generations. On the third-generation the dog and the bitch should be as unrelated as possible. this is called and outcross but should still retain a similar phenotype to the other half of the mating. This is my general advice for pedigree dog breeders who are not only working towards developing their own healthy breeding lines of quality but have a very significant knowledge and understanding of the pedigrees of their stock .But if you are a pet owner and would just like a litter to have, say, another dog or to educate your children into the mysteries of mating, whelping and weaning, it is always sensible to choose a totally unrelated male mate for your bitch.

    • Tracey Cook Says:

      Hi I have a female EB she is 6 months old and has issues with her elbows. She walks with stiff front legs. I know her mother and father have the same father but different mothers. Could this health issues have come from breeding sister to brother?

      • davidcavill Says:

        It’s possible but how do they move? If other member of the family exhibit the same characteristics it will have a genetic base. If they do not it is something new. It could still be genetic. of course.

  7. Jessica Says:

    So if I understand correctly it is ok to line breed, as long as if it is a few generations apart. But it is not ok to breed a grandfather dog to granddaughter. Rather you want to breed great grandfather to great granddaughter, is this correct?

    • davidcavill Says:

      Like most summaries, your comment is oversimplified, Jessica. All breeding in pedigree dogs is inbreeding to a certain extent but those of us who see ourselves as dog breeders think of ‘inbreeding’ as mating a dog and a bitch that are closely related and and if we mate a dog and a bitch which are related less closely we refer to it as ‘linebreeding’. Where the line is drawn depends largely on the quality of the two animals. The more ‘sound’ they are the closer you can breed. many people forget that the reason we have cows which give a great deal of milk and chickens that lay eggs everyday is because we have inbred of them for those characteristics. There is nothing wrong with close breeding but you have to know what you’re doing

      The problem has been that some breeders have mated closely animals which are themselves not sound or have some other genetic defect. The technique is to choose animals which are very sound, of very good type and as little related as possible.

  8. Joanna Reichert Photography Says:

    This is a good write-up – thanks for taking the time to make a potentially exhausting subject palatable!

  9. Tracy Says:

    I have been breeding Golden Doodles for several years. My stud is the Golden Retriever and my bitches are Standard Poodles. Realizing my stud was getting old, I studded him last summer with a Golden and took pick of the litter male as stud fee. Got a beautiful boy who looks and acts just like his daddy!! My stud has over 100 children in the world, none of which have had any health issues at all. We lost him this past spring to cancer at the age of eleven and a half.

    I bred one of my Standard Poodles with one of my first Golden Doodles and produced a litter of F1b’s, which I am very pleased with. The stud of this litter is the son of my original Golden. The mother was totally unrelated.

    I have an incredible liver colored female in this litter, and I am seriously considering keeping her. She even has a brown nose, which is unheard of in Doodles! But my stud is technically her uncle. Or half uncle since there is no relationship on the mother’s side. I loved my stud’s line and disposition, which is why I studded him to get this male. There are no genetic difficulties in his line anywhere. There are also no genetic difficulties in the mother’s line.

    Would you think this mating would be acceptable? I think it would, but certainly welcome the opinions of others! Thanks!

    • davidcavill Says:

      My view is that I would prefer the efforts of sensible and thoughtful breeders such as yourself to go towards improving the genetic quality of established breeds and see little point in developing crossbreeds which are unpredictable as far a type and temperament are concerned – there are more than enough crossbred dogs in the world already (actually, imho, too many pedigree breeds too, for that matter). However, from a technical point of view your proposed mating is perfectly acceptable. This is an interesting discussion. I will be taking it up in a future speakers corner.

  10. Tracy Says:

    Thanks for your response! Like you, I was not in favor of the crossbreeds we see for many years. But I must say I stumbled upon the Golden Doodle several years ago, and studied them with great interest. They are truly a wonderful dog! The lack of shedding with a poodle combined with the lovely hair of a golden produces a beautiful dog. I have placed many babies in the homes of children with severe allergies who had tears in their eyes saying “You mean I can finally have a dog???” and they have had no allergic reactions to Doodles. I have several placed in homes with autistic children, and the result in simply incredible. There is something about a Doodle that brings out love in an autistic child. I am not sure what it is….but it is quite undeniable. The intelligence of poodles is amazing, and goldens are incredibly smart, too. The hybrid vigor that occurs between these two lines is something else to see. I let them go home at seven weeks of age, and have had owners who wanted to train them to ring a bell when they need to go outside. Doodles can master that by day two in the new home. I have been very picky about my selection of dogs, and Golden Doodles are the only cross breeding I will ever do.

    One other thought I might post for other breeders to read is this. When my puppies go home, they do not cry at night because of two things I do with them before they go. I have had so many positive comments from new owners that I feel it is worth passing on. I allow buyers to select at five weeks of age. I require them to bring me two things when they select. First, a wire crate for obvious reasons. Second, I have them get out an old, ratty bath towel they no longer use and have every member of the family sleep with it for several days prior to the selection. I want them to wallow on it a bunch!! Then they leave me the towel. At six weeks, I place them in their crates to sleep at night, but before bed I hold each baby with their towel. (We won’t mention that I rock them and sing to them while we hold the towel. LOL!!) The towel does not go in with them at night, but is placed on top of the crate where they can still smell it. When the new owners return for their babies, they are instantly recognized by the baby. By crating them here, and beginning the separation process, my older dogs lay beside the crates all night and keep them from crying. When they go home, they are used to their crates and they do not cry. I also collect baby blankets from friends whose babies have grown up, and my dogs lay on them. Each puppy goes home with a baby blanket that smells like their parents. If the puppy is crying in the first days in the new home, a short holding with their baby blanket soothes them greatly.

    Thanks again for your answer!!! I do appreciate it!

    • David Cavill Says:

      Dear Tracy,

      Thank you for all that. Some excellent ideas in your response which I will remember (and use) and circulate.

      They will turn up on my Weblog in the next few weeks

      Very best wishes


    • Jennifer Doolity Says:

      Thank you so much for sharing these great ideas! One of my best friends has several Doodles and they truly are amazingly smart dogs! I have have a golden for 16 years next month and she’s great! Any ideas if breeding a Golden with a Doodle brings? Do they still not shed??

    • Wendy Koranda Says:

      I send a blanket home with the babies I raised with the scent of siblings and parents .

  11. Caroline Says:

    Hi David
    My lab bitch has the same grandfather as the proposed stud’s father. Both mine and the stud are PRA & EIC clear though it’s still subject to hips and elbows, is this a reasonable mating or too close in your opinion? I’m keen to use this stud as he’s the last of my original line.
    Thanks for your time.
    Caroline, Pig, Puddle & Oink!

    • Beth wood Says:

      Hi David I have male dog and wish to mate with a bitch that’s father is his grandfather all mother bitches involved are unrelated hope you can help thank you Beth

      • davidcavill Says:

        So much depends on the breed and whether there any genetic problems in its background. If both dogs are physically and genetically healthy there should be no problemhealthy

      • Esther Says:

        We have 5 healthy puppies from brother & sister German Shepherd. Same mother but different fathers. Explain repercussions if any.
        I have friend who wants to use my male Shepherd for selling & pics of her litter, but my Shepherd is not the father, his father is.

      • davidcavill Says:

        Your question is confusing. I would need a lot more detail before making any comment

  12. Catherine Says:

    Wow! What interesting comments! Thank you so much! I’ve been breeding labradoodles for the past 2 years, so Tracy, I can say without a doubt, I know where your coming from. I believe very strongly in what I’m doing as well. The joy I get from doing this so rewarding!

    I have 2 F1’s that I’ve been using, mainly because they are absolutely the best all round dogs I’ve ever had! Their offspring are totally amazing! I just finished placing the last of my litter of 11 puppies! Because of how well my puppies have been received, I already have a waiting list for next years litter!

    Next year though, I was hoping to breed my girl with my male labradoodle AND my standard male poodle. I’m really hoping to get a beautiful curly black female to keep for myself and breed later on when my female retires. So here’s my question for our very knowledgable genetics guy 🙂 … My female is cream with a black nose. My male labradoodle is all black. And my poodle is cream with a brown nose. If she were to have an all black female, would it be acceptable to breed her later on with my standard poodle?

    • davidcavill Says:

      I would say yes – black is sually dominent whatever else is in the mix. BUT beware -I have absolutely no experienced of these cross-bred dogs. Unfortunately the result of such matings will necessarily be unpredictable – one of the reason for sticking with pedigree dogs in my view – you usally know wat you are going to get from a mating.

  13. Catherine Says:

    Thanks David for your quick response! Don’t worry, I won’t hold you liable or anything 🙂 I’m just trying to educate myself before I make any decisions.

  14. davidcavill Says:

    May I suggest you go to and click through the the bookstore. There may be books which will give you much more information than is available on the Internet or in a short article

  15. Lizzie Lou Says:

    David – we are preparing to purchase a Vizsla puppy with no intensions of breeding. The puppy is from an accidental litter and we are aware that the dam and sire are half sibblings. Is this a red flag? They have the same mother who we met. The lines of both the sire and dam are documented and accessible to us.

    • davidcavill Says:

      It could a ‘red flay’ in many breeds but the Hungarian Vizla is one (of the many breeds) which is considered a very healthy breed. My view, of course, is not a guarantee but it would be one of the (many) breeds which, so long as this mating was not a regulat occurance, should cuase no problems. You should have a look at the Hungarian Visla Breed club website ( which will give you more information and provide you with some sensible question to ask the breeders

      Best wishes and good luck


  16. Rebecca Says:

    David – I’ve just stumbled upon this blog in a search for some answers, and I think you might be able to help me. I have a stunning 6 month old male boxer pup with no faults or problems, and I have recently bred my unrelated dark brindle bitch with his uncle (his fathers full blood brother from the same litter). I intend to keep a female pup from this litter to hopefully breed with my boy, which would make the breeding pair first cousins. My brindle bitch does not share any relatives with the sire of this impending litter for as far back as we can trace (we have 5 generations for the bitch, but only 2 generations for the sire), and as she was imported, it is highly doubtful that there is any relation between them further back than that. Do you think the pairing of these first cousins would be acceptable, and could you offer me any advice when it comes to picking which female pup I choose to keep out of the litter?

    Thanks for your time.

    • davidcavill Says:

      See the other comments, Rebecca. It looks a sound mating to me on the statements you make. For picking a puppy you should consult Pat Trotter’s The Puppy Puzzle which gives by far the best advice on selection available. You either need to have read this book or ask an experienced breeders to comment at 12 week. Why 12 weeks?. This is the point, according to Pat wheh the pupp is most likely to have the same proportions of the adult

      • LJ Says:

        I probally shouldn’t comment on this breed but I have purchased 2 and rescued 1 boxer . the female I rescued ended up having cancer I still have her but lost a litter of pups partially because of this . the other reason the pups were lost the male I purchased first had a sezure disorder I was told after spending several thousand dollars for medicine and on vet bills that this breed was prone to having the sezures and it was a bad idea to allow them mate . I had doubts about this and purchased another boxer and he has the same sezure disorder . My best advise is to research with breeders that specialize with the boxers and a few vets about this breed of dog .

  17. Mike Ferrar Says:

    I am very pleased to have discovered this site. David, your article is hugely enlightening, thank you. I also found Tracy’s comments, and in particular her strategy on comforting newly placed pups when going to their new home, helpful. I am breeding English Springer Spaniels, and have discovered that the Sire (Murray) I propose using on my two Dams (Georgina & Harriet – mother and daughter) is a first cousin to Harriet i.e. Harriet’s father, and Murray’s mother were brother and sister. I will put Georgie to Murray, as there is no relationship going back through 5 generations. Would it be advisable or not to put Harriet to Murray? Would it be advisable or not to put Harriet to one of Murray and Georgie’s dog pups, given that Harriet is Georgie’s daughter? Thank you, David.

    • davidcavill Says:

      Thanks for your comment. Mike. I am very pleased there are people out there doing some sensible research before mating theri stock. Having said that – I cannot advise you because, as wilt all these quesions, ‘it all depends’. If the dogs are sound, helthy and their relatives live long lives free from disease or pain (and have you have done the relevant tests) then I see no problem at all. You can breed quite closely so long as the dogs are sound.. But if there is a history of helth problems then I would avoid. Good luck.

  18. luis Says:

    i am thinking of buying a new german shepherd puppie for breeding and i realized the my male have the same great-grandfather, it this ok and if AKC will it register.

  19. travis Says:

    i was thinking about breeding to pups that have the same sir but diffrent this ok in the line breeding

    • davidcavill Says:

      If you do I would mate to an unrelated dog/bitch but, like most of these questions I would need to know a great deal more about the propsed dogs before making a meaningful comment

  20. Rich Says:

    I just got an irish setter female pup and I registered her through the AKC. When I got her history, I see that her mother and father had the same mother with different fathers of two seperate litters. If I am reading your article correctly, this is not really a problem however not being a breeder, it is strange to me. Is this something that should have been disclosed to me prior to purchase or is this a pretty common practice? The dog is great with no known defects at this point. Thanks.

    • davidcavill Says:

      It is not uncommon and should not be problem – although much depends on the breeding behind the parents and grandparents. I assume you have the pedigree so the relationship has been disclosed

  21. Emily Lewis Says:

    Hi David,
    We are considering buying a labrador pup where the sire is the same as the maternal grandfather. We currently have a dog from this same sire. He certainly has the all the qualities you look for in a labrador, is both an FC and an AFC with an excellent temperment. The dam is also of this same calliber, both are CNM, EIC clear, excellent hips and elbows and eyes are certified. Any suggestions, is this too close? It is a repeat litter and the breeders were very pleased with the first results.

    • davidcavill Says:

      Dear Emily,

      You have clearly done your research – good for you. From what you same I think the puppy will be fine. The breeding programme is standard good, line breeding practice when all the dogs are sound

      • Marlene Says:

        Hi David,

        It’s great to have come across your site. We find ourselves in a similar situation with an uncle/niece Lab pairing. Both are healthy and have all their clearances, including heart, with the exception of the niece who is a carrier for HNPK which she inherited from her father (no relation to the uncle). The pup we would be getting is from their 4th litter together. What are your thoughts on this? Is this too many litters from this pair?

        Many thanks!

  22. Cynthia Says:

    Hi David,
    I have a 3 year old yorkie female and I was thinking about taking in her brother in another month. He’ll be 2 months old at that time. Being that this is her parents 4th litter of pups, would you it be ok if I eventually mated this sister and brother or would you not recommend it? Thanks in advance.

  23. Donna fowler Says:

    Hi, I love this subject! My bitch has the same father as my studs grandfather, trying to work it back I think they are second cousins so could this be a mating? Kind regards

  24. Karen Says:

    Hi, I am looking at getting an Akita puppy. The breeder I am keen on (not many Akita breeders in my country) is going to mate the grandson back to the grandmother. She genetically tests the dogs for the major defects. Would you consider this ok? Thanks

  25. Julie Says:

    Hello David. Like many others on here I have stumbled across your article on line breeding. I have a 12 week old Bichon Frise and studying her pedigree I see that her parents both share the same father, making them half siblings. It appears that our breeder has used the same stud kennel for their matings and the stud kennel operates selective line breeding with many of their dogs being champions all with exemplary traits. Our dog was the only one in her litter and though we love her dearly she is showing issues with dominance and has been aggressive on a couple of occasions. For this we are taking her to a behaviorist in the coming week. Do you think her breeding could have a baring on this or do you think it would be more likely to stem from the fact that she was the only pup? I believe we’ll get there with her in the end but in retrospect feel we were quite naive when it came to choosing her.

    • Julie Says:

      Just looked at the kennel club mate select online link you gave to the previous poster. Our dog comes out with an inbreeding coefficient of 22% where the average for the breed is 11%. Is this really bad?

      • davidcavill Says:

        Dear Julie,

        No it is not – it is similar to cousins marrying in human terms. However, you should find a dog which will lower the Inbreeding co-efficient. Going for a dog with the breed average would be the right direction.

    • davidcavill Says:

      Dear Julie,

      Temperament is much a factor in selecting a mate for a dog as anything else. You should be looking for a dog which is calm and biddable. Not all the puppies will necessarily take on those characteristics – but some will and, again you will be going in the right direction. In looking for a behaviorist I would ask whether their are a member of a professional organisation wand whether that organisation is a member of the Pet Education, Training and Behaviour Council

  26. kim Says:

    im breeding my vizsla and notice her and the stud have grandparents from the 4th and 5th generation is this ok

    • davidcavill Says:

      Vizslas are a generally healthy breed – It is not something I think you need worry about. With otu seeing the pedigree I guess it is a good line breeding


  27. Jennifer Says:

    I just got a male golden puppy to breed with my female sometime next year when looking at their petagree’s I see they have the same grandfather on the mothers side. is this to close to breed?

    • davidcavill Says:

      All other things being equal (the dogs are sound and healthy – and I have not seen the full pedigree) having the same Grandfather is not something to worry about

    • tori Says:

      I have a sir that has a fifth generation sir that is the exact same sir as the second generation of my bitch, my question to you is can I breed them safely and will it affect AKC registration for the puppy’s by any way? Basically is that legal per akc?

      • davidcavill Says:

        I would think so from a genetic point of view (other things being equal and I do not have access to the pedigree so could not be sure) – but you would have to ask the AKC if it is within their rules. I assume your dogs are AKC registered

  28. Lis Says:

    Hello, David,

    I bred my two German Shepherds not long ago. They are father and daughter. Both are excellent dogs mentally and physically. I have read and studied much on the subject of Inbreeding, studied the pedigrees of both dogs (which have come from high-quality, line-bred stock) and provide them with the best care possible–mentally and physically. They are sound.

    Is there anything wrong with my decision to breed this pair? You mention often in your blog, “…so long as the dog is sound”. Health of my dogs is most important. I believe that the pairing of this relationship was a good one…but I get some nasty remarks from people about my having done something “immoral”, and that nothing good will come of it.

    What is your opinion, please?

    Thank you. I appreciate your reply!

    Best regards,


    • davidcavill Says:

      I could not say. I would avoid such close mating unless there was an exceptionally good reason for them. This does not mean that they are wrong – just you have to know a great deal about the genetic health of the dogs in question as well as their being of sound constructional and physical fitness. Under UK KC regulations (not one of which I approve as there is no legal precedent) the pups from this mating would not be registered which indicates the concern which canine authorities have over the issue. Also. to be quite frank, I have seen few GSDs which would qualify for matings this close. This does not mean you are wrong – just that without seeing the dogs still and working and their pedigrees and test scores I could not say whether it was a sensible decision.

      • Nicole Says:

        I had a litter of pups with a Australian Shepard and Golden Retriever. Both health tested normal . We kept a puppy which is now 2. My male father got out and tied with the daughter Australian retriever. How bad is this? Should I take her to the vet and abort? I have a male golden retriever I was going to mate her with. Should I still let them mate for several sessions? I plan on fixing one of them so this won’t happen again but I need to know how to proceed now since this just happened yesterday.

  29. Talha Zaheer Says:


    It was great learning from this blog. I don’t think I have a unique predicament, but nonetheless I thought it would be better to refer to an expert. So here goes:

    I have a beautiful red nose pitbull who is as friendly a dog as they come. I’m based in Pakistan right now and over here you are hard pressed to find a pitbull of this quality. He is only 10 months and is already bigger than his father in size (Mother is the one that gives solid colored pups and provides the size as well). I have a lot of people approaching me with studding offers. He recently won an FCI event here as well and I have literally had traffic stop and people climb out of their cars to play with him (after initial trepidation because its a Pitbull).

    From the little I know, one shouldn’t allow the male to mate until he has grown to full size (thus I’m planning to wait till he is 1.5 years old). Secondly, I have been looking for a suitable partner for him to preserve a quality red blood line in my region. The trouble is that just about every other Pitbull here simply does not compare. The only female worth mating him with is his actual sister. Provided both siblings are stable and have fantastic temperaments and are generally friendly, would it be advisable to mate them and then for me to select a female pup from the litter produced as a long term companion for my dog? Some guidance will help. It is pretty expensive importing quality dogs and alas other Pitbulls in the country are either lacking in size, looks or temperament. This is making me consider this route.

    Finally, when do you recommend for females to be mated? Skip the first two heats? How does mating affect the physical attributes of the animals that have been mated (based on age etc)? Would love to gain some insight. Thank You and Best Regards,

    Talha Z

    • davidcavill Says:

      All Golden Retrievers are descended from four puppies of a mating between a indeterminate retriever and a Tween Water Spaniel. In the wild many groups are closely bred – but you have to remember that in these circumstances (and this includes dog breeding) any offspring not absolutely fit died naturally or, in the case of dogs, were culled. As I said in a recent post – I would avoid such a meting unless there was an exceptionally good reason for it – but your post indicates that you have given the matter a great deal of thought so I would go for it – remembering you will have to make very careful assessments of the puppies and be prepared to cull any that show signs of unsoundness or aggression. This may not be politically correct and you may have to put up with criticism. You are the only one who knows whether you can handle that!

      • Donna Cox Says:

        hello David…just wanted to point out that the gentleman who sent this question, Talha Zaheer, was asking about a pit bull, not a Golden Retriever, as your answer indicated. I didn’t know if your answer would change if you realized he was talking about a pit bull. Also..he also mentioned the two dogs are BROTHER AND SISTER….in all of your past views on breeding brother and sister your answer has been “absolutely not”….it confused me a bit, and as a simple courtesy to both you and him, I just wanted to point this out. You can tell me to mind my own business lol. …it wouldn’t offend me…i simply wanted to bring it to your attention. Thanks so much! Highest regards. …Donna

      • davidcavill Says:

        I cannot track this down but I would not mate brother and sister – if I said it was OK I did not read the post properly.

  30. Talha Zaheer Says:

    Thanks David. Also could you shed light on changes in the dog’s body structure based as a consequence of mating? Does the height of the male dog really stop growing once it’s mated for the first time (and is the same true for females)? Moreover, I am also told that there is a marked change in temperament (cooler) after having been mated. As someone that owns a pitbull, I know not to go by the rumor mill- my dog is as friendly and playful as any lab, yet despite the friendliness is a fantastic guard dog.
    Really appreciate you sharing your wealth of knowledge!

    • davidcavill Says:

      Mating a dog or bitch has no impact on their size. Dogs will grow until they reach maturity. But once a bitch had been mated her temperament may change a little (perhaps be more affectionate or more protective) but, in my experience not by much A dog’s temperament may change a little too – he will be more anxious and difficult to manage if there are bitches on heat about.

  31. StevenMD Says:

    HI my wife and I are looking to get a pocket beagle from a breeder who states that the puppy that we’re interested in has been born through 2nd cousins (not sure what the dog terminology would be for that). If this is true, are there ant defects we should be aware of? Also the puppy doesn’t look like it has any defects but is there anything we should be aware of further down the road?

  32. hatem zalloum Says:

    Hi David, An impressive article indeed & I thank you for it,,
    Wanted to ask you about breeding my german shepherd male who comes from germany and is a truly super quality ‘his grandfather is a world sieger”, mind u, half his siblings had floppy ears!!!!! Would he pass on the “bad ear gene”? noting that the female I am considering has few sibling with soft ears too”she also comes from sieger blood lines”!

  33. Hello David, a great eye opening article indeed & I dearly thank you for it.
    I have a super german shepherd male imported from germany with a super pedigree “a grand son of a world sieger” mind you, half his siblings have soft ears!! If I breed him, would he pass on the bad ear gene? Especially that the female I’m considering also had some litter-mates with soft ears!
    Thank you,

    • davidcavill Says:

      I think you need to talk to a GSD specialist. I do not know the genetics regarding ‘soft’ ears but it is likely to be a complex mechanism and not the result of a single gene – and it may well be different in different breeds. The ‘natural’ ear set is ‘pricked’ as can be seen in Caanan Dogs and Huskies be GSD are a long way from this genetic framework.

  34. Anne H Says:

    Hi im talking sheep, I have a ram by x out of a ewe by Z most of my ewes are by Z or there grandmothers are by Z .Can i use the ram back on anything please

    • davidcavill Says:

      It sounds as though your stick is becoming quite inbred. You need to work out the Coefficient of Inbreeding (the is a link in this or another of my posted articles) and keep the % below 12.5

  35. Question…In your opinion, Is it to close to breed two dogs from the same sire, with different dams and and a year or two apart in age? or even the same age for that matter.

  36. Pat Says:

    I have a stud bulldogge his parents are the grandparents of a dam I acquired through a trade. I was not aware of this at the time of the trade. Do you think this is too close? I have received conflicting answers. I plan to acquire another stud within the year so I can wait to breed her. That is not the issue. I am just curious. Thank you. Pat

    • davidcavill Says:

      I do not think this is too close but you should have a through knowledge of the breeding history of all the dogs you intend to use and base you decisions on their having sound genetic and physical health

  37. Lisa Says:

    I am looking at a litter that is related to my current dog. I just love her to bits 🙂
    The dam’s mother is the same breeding as my dog, the father is an outside dog
    The sire’s mother is an outside dog and the father is the same breeding as my dog (and the dam)
    I think this works out to a niece and nephew with 2 outside dogs being breed.
    I am having a hard time following the inbreeding and line breeding and just wondered what this was 🙂
    I thank you for your input!

  38. jamie Says:

    Hi David, thank you for a great insight into breeding. We breed Miniature Dachshunds. I have recently been offered a dog to add to our breeding, he is from the sister of 1 of our dams. Would he & his mothers, sister be a good mating in your opinion. Our dogs are all PRA clear and have great temperament.



    P.S Thank You Tracy for your sharing of that experience it is something we will definitely be adding to our breeding.

    • davidcavill Says:

      Sound good line breeding to me – subject to all the other heath checks of course. Do you get the Dachshund Breed Council Newsletter. If you do not you should. You can join the list from their web site

  39. jamie Says:

    Thank you, for your reply..we have all our dogs health checked & DNA tested before even considering breeding them. The dog we are looking at is of excellent lines, and parents also have great temperament, as has the dam we are looking at mating him with. Will look at getting that newsletter for sure.
    Thanks again,

  40. Lou Says:

    Hi I’ve just brought I make chihuahua 2 mate with my bitch I’ve just realised when looking at both pedigree papers that the mum of my boy has the same grandma but not grandad but the dad of my bitch has the same grandad but different grandma if that makes any sense

  41. kat Says:

    Hello there..I am about to buy a golden retriever male pup whose mother is the sister of the bitch I already have . When the male matures I would like to breed them I right in saying then this new male puppy will be my bitches nephew ? all dogs have clear hip / eye tests..would this be too close to mate them or does it come under line breeding ? the pups have a different father than my adult bitch

    • davidcavill Says:

      Its quite close – you should ensure any recommended tests are carried out on both dog and bitch before you mate them and ask yourself why you want to mate these two particular dogs. If it is just cheaper than gping to another stud dog you might want to think again. A goof stud dog is not ‘cheap’ but compared to what you would get from selling the puppies is is very reasonable

  42. Rachel Nimmo Says:

    Hi I need help I have a staff cross bitch who I want to breed with a pure Irish blue staff The dog is the bitches grandfather on the mothers side ?? Can u help

    • davidcavill Says:

      Would not be a problem if there were no genetic or physical defects – but I would ask ‘why?’ If you like SBTs, what is the objective in breeding from a cross bred bitch?

  43. Anne Says:

    I have a female Amstaff (ky) my mum owns kys brother ( Boof) ky recently had pups completely unrelated english staffies father (jet) female puppy (sapphyra) my mum would like to know if she brought Ky & Jets female pup Sapphyra could she breed with Boof all 100 % healthy if Sapphyra passes all health checks when she becomes breeding age?

  44. Pamela Doyle Says:

    We have registered Shetland Sheep & have been breeding for several years. We are interested in breeding a ewe & ram that have the same sire & completely unrelated dams. What are your thoughts on this breeding?

    • davidcavill Says:

      I know nothing about sheep or whether or not there are any genetic defects in this particular gene pool. However, if they are both healthy (and the Inbreed Coefficient is not high – you need to look further back in the pedigree to see how closely they are relating in the past) it seems a sound mating

  45. Steffi Says:

    Urgent question. I am about to buy a labrador retriever puppy and am considering pus from 2 different litters.
    In Litter 1, the dam’s mother is also the sir’s grandmother. In other words, the dam is half-siblings with the sir’s father.
    In litter 2, the sir’s father and dam’s mother are half siblings.
    Are both of these sound matings? Thanks so much!!

    • davidcavill Says:

      Like all these questions you need a great deal of information – and even then you cannot be sure. In theory, all other things being equal, there should not be any problems. It sound good line breeding as far as I can tall

  46. Steffi Says:

    Thank you so much!! I’ve found some breeders can get a little touchy when asked too many questions.

  47. Tyler Says:

    Ok I have a question. In reply to Jessica’s question (from feb 2012) about breeding great-grandfather to great-granddaughter, you said her answer was over simplified. But never gave a definite answer. And then went on to say that the line was drawn by the the “quality” of the dogs. But in reply to to others such as Stacy (from August 2011) you say to not breed the father to daughter and that the kennel club would not register them, Which tells me the line is drawn by more than just the “quality” or how sound the animals are. So I guess what I am asking is, is there an exact answer for how many generations you need to have in between the male and bitch you are breeding? Or is it primarily up to the Kennel club your registering with? After reading the summary I still don’t feel like there has been a straight answer as to the difference between line breeding and in-breeding. I fill like it has been filled with a lot of scientific and genetic jargon and no definitive answer has been stated. But maybe it is me and my ability to understand what it is you are saying in this weblog. So any answer in laimens terms would be GREATLY appreciated lol.

  48. Acheron Says:

    I am looking at buying two American Bully dogs to breed, but they aunt and nephew, is that considered acceptable? They bitch is a sister to the sire of the male dog I am wanting, but no relation on the mothers side whatsoever. Neither side as any known issues. The breeders say it is acceptable but just wanted to make sure. Thanks.

  49. Susan Crowley Says:

    Is it safe to mate my girl Chihuahua with a stud dog that has the same dog as his grandfather and my girls father, coefficient came out at 11% average for this breed is 7%. Thankyou

  50. Alex Says:

    I have a 4 yr old female and just recently got a 10 month old male, I plan on getting him fixed but was curious if they did accidentally mated what could happen? they have the same mother but different fathers and being 3 years apart with many litters in between.

  51. davidcavill Says:

    How far apart the litters is irrelevant. As always, it is not possible to give specific advice but if both are healthy it should not be be problem – but it is too really close

  52. Alex Says:

    does the fact that the dogs have different fathers but same mother matter?

  53. vamsi Says:

    i wold like to ask. my female dog had a son he had a son with another female can i place his son to his my female ??? that means grand son to grand mother…..

  54. Ingrid Says:

    Hi David, I am looking at a Havanese puppy where the parent dog and bitch have the same mother but different fathers. All recent generations are well bred champions and no cross breeding there. The pup seems to have a good temperament. What do you think?

  55. andrea Says:

    hi I have a question I hope can be answered these are American bulldogs my daughter sold a pup that is a grandchild to my sire and my sire and a new female with no bloodlines to any of my bloodlines are having a litter the person who bought my daugthers pup wants one of these new pups to breed with his dog meaning that the sire is the grandfather and father of the new pup none of the other dogs are related….he has good bloodlines been tested and is 6 yrs old with not a health problem in him what are your thoughts as they asked me and I have never inbred any of my dogs so have no answers

    • davidcavill Says:

      Getting too close I would have thought – but it all depends on the health of all those involved – but why does this dog have to be used?

      • Amber Says:

        I am so glad to have found your site. I have a question for you. I purchased a male and female French bulldog for breeding. These dogs came from different breeders. After looking at their pedigrees I realize that my females dad is my males grandfather. They both have great temperaments and are very different in size. My female is chocolate and carries blue. My male is blue and carries chocolate. Is this too close for breeding?

      • davidcavill Says:

        As always – both dogs must be sound. If they are the relationship between them is fine. Without seeing the dogs is sounds like good line breeding

  56. kim Says:

    Ok, I have looked into line breeding and cant really get a good outlook on it. I have a male I got from a breeder that does line breeding. I love their dogs. They are very correct and healthy. I would like to purchase a female from them but am unsure. The female I am looking at is related to my male down in the pedigree. They produce all their females through their founding female. He is the son to that female and I am unsure how far related the mother to this female is. Ill try to give a family tree. female I want to buy= mother( same sire and grand sire to my male in her pedigree although not sure how far back), Father to the female( same sire and my males grandsire). This female is 2/4 linebred on my males grandsire.

  57. Andrea Says:

    Hi, I have miniature schnauzer girl, my friend has male, we want to breed the two of them but, we know my girl is aunt to her male is nephew ( my friend other male dog is my girls brother , he’s father to male I want to breed with ) would this be to close? both dogs have eye checks and are in good health

    • davidcavill Says:

      A little close – it depends on the rest of the pedigree. Are there any other relatives in any areas of the pedigree not directly related to you dog and bitch? If there are not it should be OK

  58. Maria Says:

    Thanks for an interesting article! I want to do a mating where the COI calculated from 10 generations is 11, and the 5 generation COI is 4.5. The sire, dam, grandparents and other close relatives we know abaout are healthy. Would this mating be okay, or too close? When calculated from 10 generations what COI should breeders strive to keep under in a rare but generally healthy breed?

  59. Maria Says:

    In 5 generations? But what about when counting from 10 generations?

  60. Angel Snow Says:

    Hi David, we have a half boxer half pitbull, the mother was a purebreed pitbull and the father a boxer. The mom had another litter with a purebred pitbull. We wanted to know if it’s ok to breed them where there half brother and sister. We want to keep her blood line going where she’s an amazing kind dog.

    • davidcavill Says:

      A little close – it depends on the rest of the pedigree and the soundness of the two dogs. Are there any other relatives in any areas of the pedigree not directly related to you dog and bitch? If there are not it should be OK

      • Angel Snow Says:

        The only thing linking to both dogs Is the mother. There no other relations throughout. The mom has no health conditions neither did her mother. I’m not sure about my girl dogs father. I but the boys father is healthy and has no issues that we’ve been told. My fiance and I don’t want to breed them, if iit’s not good for them. But also want to keep her blood line going.

  61. cris Says:

    hello David, I have two Siberians huskies, they are brother and sister, same parents, same litter. I researched about the consequences if they would breed, and I found all kinds of possibilities and risks, but is all uncertain. Could a just run some kind of DNA test? to both to have a definite answer to find out if it would go with out problems instead of speculations and possibilities with out certainty.

    • davidcavill Says:

      I do not think DNA test would provide any useful information. Sibel are a pretty healthy breed but I still would not mate brother and sister. Apart from the fact that you would not be able to register the pups with the KC ithe CoI is too high for comfort. It has been done but usually by accident or by those who are very experienced.

  62. Jane Says:

    Unfortunately the COI’s are very misleading on the KC website, especially for low founder breeds. COI’s are only as good as far as you can go back. Take the Cavalier King Charles Spaniel that apparently has an average of 5.2% but this breed was only seperated from the King Charles in 1942 and had only five stud dogs as founders. If the KC where to actually go back as far as it records can and calculate its COI, the COI will be a lot higher than 5.2%. I know people who have taken the time to go as far back as records allow with their dogs and the COI was then doubled or in some cases even more than doubled. I’m afraid its smoke screens and mirrors and if you truly want to get a more accurate idea of a pure breeds COI you need to roll up your selves and do your own home work, as the COI’s calculated for breeds on the KC website can be misleading. You really need to know how many generations the COI is calculated over and in most cases it often is manipulated far enough ahead, so the low founder issue of the breed is not truly reflected in the COI.

    • davidcavill Says:

      You are quite right, of course and the same would be true of many long established breeds – all Golden Retrievers, for instance, can be traced directly back yo just one male and one females and all life can be traced back to (probably) just one cell! But the convention is to work over 5 generations as, within that time, any serious problem which is going to arise is likely to have made itself known.

      • Jane Says:

        Who’s convention is it to only use 5 generations ?
        Selective breeding in dogs as only been around for less than 1% of the evolution of canidae, so tracing back to one cell is a bit of a silly asperion on the calculation of COI’s for pure breed dogs. We are talking about levels of inbreeding in dogs not evolution of species. If the Golden Retriever as you infer has only two founders ( I seriously doubt this and I suspect that dogs like in other breeds have been allowed on the register in the early days with unknown breeding but of type, as foundation stock), then calculating beyond five generations is even more warranted in trying to keeping what genetic variation in the breed there is from depleting even more.
        Ten generations is good but to really get a true picture, as far back as you can until the pedigree information stops, so most we are talking at around twenty or more generations. Looking at a dogs COI, as you know is to calculate its homozygosity (doubled up of alleles) in an individual due to the same ancestors showing up multiple places in its pedigree. No matter how many generations you look at, the dogs pedigree/ancestory won’t change. Consanguinity has created a level of inbreeding in a dog and that will not change, only the willingness to see it.
        More information is always equal and in the most part better than less information.
        We know it can take more than five generations before people start to realise they have an ancestor with a problem and have saturated a line with its blood. Convention should never stop people seeing the full picture and only looking at five generations is like just letting the sunlight peep through the curtains, instead of pulling them right back and letting the light flood in.
        I would of thought it better to advise people to get as much information as possible before breeding dogs and as I said before, “if you truly want to get a more accurate idea of a pure breeds COI you need to roll your sleeves and do your own home work.”

  63. davidcavill Says:

    You are right, of course and there is no internationally recognised ‘convention’ just years of experience and practice – and the KC,decitsion of course. My comment about ‘one cell’ was tongue in cheek but there comes a point (5,6…12) generations when calculating the CoI becomes pointless – partly because damage and naturally occurring changes in DNA (and accidental or purposeful matings outside the breed) mean that succeeding ‘copies’ are inaccurate so negating the validity of the CoI. The key question is ‘What are you trying to achieve?’ and for most people 5 generations is enough. For others (perhaps in breeds with very restricted gene pools) then more generations are necessary. My wife and I bred very successfully from a relatively narrow gene pool for many years (see without once referring to the CoI – although we did study pedigrees and assess many dogs, bitches and their offspring in the UK and abroad very carefully. There are more ways than one to kill a cat so although the CoI is important is it but one tool for the concerned and successful breeder.

    • Jane Says:

      Exactly using COI’s over just five generations really serves no purpose and most should be able to read a pedigree and see interfamily connections easily.
      It only becomes pointless when the pedigree stops giving information and obviously we will have to agree to disagree on when it becomes pointless. Five though is also pointless, unless you are unable to understand pedigrees.
      If you are wishing to win in the show ring and your aims are short term, say your lifetime, using just a five generation pedigree as you have shown will acheive your aim but for breeders hoping for the survival of the domestic canidae for many generations of humans to enjoy in the distant future understanding the COI further back than five generations is of more significance.
      I am trying to acheive steming depletion of genetic variation in the domestic canidae. We have already lost from selective breeding since domestication of wolves 35% genetic variation by selective breeding and as we have only been doing selective breeding for less than 1% of the canidae evolution, that’s a frightening figure, we do though see only a loss of 5% in street dogs and mongrels.Genetic variation is the key to survival in the long term, just look at humans.
      Sorry to of troubled you as I now understand that this site is more geared to a breeder wishing to breed for the show ring and feel a bit of a fool for commenting on here now.

  64. stephanie Says:

    I was planning to breed my female with someone else stud I noticed that my female her great grand sire is the same as the studs grand sire. would that be considered line breeding? I have been trying to read up on this as I was a male that’s going to compliment my female to get the standard of the breed. could you please tell me a little more about what this type of breeding could bring us? good or bad. btw they are Siberian huskies

    • davidcavill Says:

      Unless either the dam or sire has a genetic or conformation problem (unlikely in Siberian Huskies – they are generally a very healthy, sound breed) I would go for it. Of, course, if you want to show or race then you will have to take the charcteristics of the pair into account but if you just want a litter of Sibes that should be fine from a health point of view

  65. Gael Loro Says:

    This is wonderful information as I didn’t know what line breeding was. I have a question: I am considering purchasing a Cairn Terrier (bitch) who’s mother’s parents are first cousins. The sire has no line breeding what so ever and no connection to the bitch. Would this be, in your opinion, ok?

  66. Erica Says:

    My sons great grandpa had a baby with his first cousin, my sons grandpa, does this effect my son at all?

  67. jackie Says:

    Ok my question is is i have a male and female from the same mom and dad i know i cant breed them but the lady i got them from wants to breed my male with one of her females that is not related to him at all she says that if i get a male out of his litter he would be ok to breed with my female(his aunt).what is your take on that?I have siberian huskys.

    • davidcavill Says:

      It is a little close but if both dog and bitch are really sound it is feasible. But if you want to mate your bitch you should use a proven quality stud dog. There are plenty of excellent Siberian Huskies around

  68. Nicole Says:


    if you have a bitch who’s dad is the same as the stud dogs granddad, can you breed this or is it to close?

  69. Loulou Says:

    Hi I have a bitch mother and father are both top line kc pedigree labs but she has mated with her father I found them in a tie he lived close few blocks away he ran off and got with my bitch who was in our back garden so father and daughter mating then an hour later my neighbour had her friends visit bitch was out for a pee and this dog jumped the fence and mated full tie he’s also kc reg top spec owners not happy at all about it but was wandering if pups would be ok we looked at five generation pedigree on mother father and other dogs papers and all are top line no inbreeding before as far as we can see

  70. Nikky Says:

    Can i do a mating between my german shepherd male and his neice.? Males mother is neice’s grandmother.Can i expect any problems? Thanks

    • davidcavill Says:

      I would need to see photos of the dogs. There are many GSDs I would not mate whatever their parentage but that said, so long as the dogs are healthy and sound there should not be a problem. It is close but not too close. Unless you have a specific objective why not use a totally unrelated dog?

  71. Nikky Says:

    Hi,is there anyone moderating this site ?

  72. Hi,
    I have male and female boxer who have common grandfather and great-grandfather. In addition that same dog appears in my sire’s 4th and 5th generation pedigree. Would it be OK to breed my dogs.

    • davidcavill Says:

      As always – it all depends on the health and quality of the dogs themselves. Genetically it is not too close but every dog and bitch must be assessed carefully if you want to retain characteristics and health

  73. Jade Says:

    Hello there David,
    I am going to be welcoming a little Yorkie into our lives in the next few years but before we choose our breeder e.t.c could you tell me what to ask the breeder for best health concerns e.t.c? Should I choose a breeder that uses an outcross ? I’m very clueless when it comes to all of this and just want to ensure we are chosing the best for our future furr buba 🙂 Thank you (if you wouldn’t mind emailing me when you get the time, I would GREATLY appreciate your advice) 🙂 Thank you

  74. I have a female and I am looking at getting a male for her. The male I am looking at is a grandson to her father. A little history of that is as follows. Her dad is Peppy. She was from a litter from Molly. Peppy fathered another litter with Sienna and that Puppys name was Scooter. The puppy I am looking at getting is a puppy from Scooter and a female that is not related to any of these. Can I breed her to him (i guess he would be a cousing sort of)????

    • davidcavill Says:

      As always – it all depends on what you want. What is the breed? – you can mate more closely safely in some breeds than in others. And to retain characteristics in breed such as Boxers and Bulldogs you need to line breed (carefully). If the pedigree is ‘open’ even thought the pair may be related to the extent they are then there should be no problem.

  75. Actually I guess it would be her nephew not her cousin.

  76. Jake Says:

    I’m considering mating 2 dobermans for just 1 litter. They have the same parents but there is a 2 litter gap between them. No known health issues with any of the dogs from the breeder I bought my dogs from. Both are healthy good looking dobbies but I’ve heard two different answers to my question, which is why I wanted to ask the master!

    • davidcavill Says:

      Don’t do it Jake. You could not register the puppies with the Kennel Club (assuming the parents are both registered) in any case as the KC will not accept registration from brother/sister matings. And they will not do it because there is a reason – it is too close. Incidentally, the fact the parents were from different litters makes no difference.

  77. kendra Says:

    Pig farming question. .. can I breed an uncle with his niece? I have 4 piglet 2 are girls and Im gonna sell them if I cant breed….

  78. kim Says:

    What about English cream goldens brother to sister different litter mates

  79. Connie Says:

    my female is small … maltipoodle … I just rescued a same breed …
    so they said … but he is much bigger like 3 times her size … and
    I now realize she is in heat … can they breed? which one determins
    the size of the pups?.. I will NOT wager loosing her!! THANK YOU!

  80. Leanne Says:

    My neighbour just got a 6 week old female pup who has the same father as her 2yr old male so they are half brother and sister, she is planning to breed them and I said I would try and find some information for her. Is this possible?

  81. andrew Says:

    I was thinking of breeding my female pit bull with one of her mother’s new puppies same father yous that OK

  82. Ozzy Says:

    Can I breed my pit/bull dog and her purebred pit father?

  83. Mary Says:

    I am a breeder of German Shepherd Dogs. Czech working lines. I don’t inbreed, but one of my females (age 2 years 1 month), got loose and tied with one of my males (age 1 year 11 months), by a huge human error. They are 1/2 brother and sister out of the same father, also both dogs have different mothers, but the mothers are full sisters. Will this breeding be bad, all my dogs are 100% healthy, no genetic problems at all. I would NEVER have breed them, but they did tie once on day 14 or 17 as close as I can figure. My vet tells me, they can’t give my female anything to slip the pups, it’s only been 6 hours since they bred. Will she take? Will I have problems? This female, is scheduled to breed on her next heat cycle to a new stud dog I purchased for her, I just want to try and figure out what may happen if she does catch.

    • davidcavill Says:

      I sympathise. But if your dog and bitch are sound I would let it go – you might get something fantastic!

      • Mary Says:

        Thank you David, yes, my male and female both are 100%, I had her scheduled for her OFA after this heat cycle she is in now to be done. When it rains, it pours! I just don’t want anything to happen to her, and now that this has happened, to have healthy pups. And, YES, who knows, they might just be awesome dogs too! My lines are good, and my dogs have great drives, temperments and dispositions. I guess all I can do is deal with this and see what the future holds. Thank You for your reply.

      • Mary Says:

        David, I will ultrasound my female next week after 21 days, is this considered “In Breeding”? What do I call this litter from your stand point? I want my clients to know exactly what this litter is and everything about the pups. Thank You.

      • davidcavill Says:

        Please read the article agaiin – I am afraid you have not understood it

  84. priscilla Says:

    Hi I was actually interested in purchasing a german shepherd from this breeder. She says one the dogs backs is too long and she wants to fix it. Both sire and dam are in line bred only to fix the problem but the breeder assure me that it was several generations back. I’m not sure how to read their pedigrees but it is from the Q litter. If you can please tell me what effects the puppies will have.

  85. priscilla Says:

    I found out that they’re grandmother’s are sisters.

  86. Mary Says:

    Ok, Priscilla, just didn’t want to be someone that I am not. This thread was a mistake “Tie”, and I wanted David’s opinion. I don’t inbreed or line breed. But now I have this “Tie” that might possibly be an upcoming litter. I just want my dogs ok, and litter puppies ok.

  87. priscilla Says:

    David- the sire and dam of the puppies do share common ancestors both dogs do look solid. I have heard nothing but good things from people who purchased her dogs. So I’m basically wondering what effects the puppies will have. They should be born any day now. Well the sire and dam have the common ancestor Their grandmother’s are sisters.
    I looked through the pedigree and line breeding took place one this occurrence as well as another occurrence the grandmother’s sisters they share. The line for this was only showing line breeding as 5 generations back but did show these.

    Occurrences. Wrights
    5-4. 0.40%
    4-5,5. 0.39%
    5-4,5. 0.40%
    5-5. 0.20%

  88. davidcavill Says:

    Good luck – you are doing al, the right things as far as I can see

  89. Emma Says:

    We r thinking of breeding, our dogs are from completely different lines of breeding but they share a great grandfather, he was a champ so he must have been stud to many different bitch dogs and had many pups. Is this okay to breed?

  90. stefaniernst Says:

    Hey David, thank you for your page and all the information. Are there any books you can advise me to read on the subject of line breeding. I’ve downloaded the program and will do my own tests, but if I could have your advise it would be great and immensely appreciated. We breed with French Bulldogs. I’ve now send in my Studs certificate and I’m waiting for the new one…so I can not give all the details on his side. But lets assume for now that the inbreeding coefficient of my Stud and Bitch is at 0%. They’ve just had their first litter, of two bitches. I want to keep one. A new male puppy became available from the same breeder where I’ve bought my stud. So they have the same mother but different fathers. So my new bitch’s grandmother is the mother of the stud I want to mate her with?

  91. stefaniernst Says:

    Thank you David! I’ve tried to download the program…but it is not for Macintosh users….Is there an alternative program for Mac users?

  92. Duane Says:

    I have someone who has a female bulldog and she wants to breed to my male but in her pedigree and my males pedigree we have a great great grand dad that is the same male, can I breed to this female without problems

  93. haley lindsay Says:

    My next door neighbor bred a sister and brother, and a son and mom, I want to buy one of the puppies, but I’m not sure if it will just die because of genetic defects. None of them are registered, (not even the moms and dad) they are huskies, and the dad could possibly have a respitory problem. Please advise on what I should do!

    • davidcavill Says:

      I would not and in my opinion the breeds are behaving irresponsibly. The pups may be fine but the risk of problems is greatly increased with such matings

  94. shay Says:

    I am looking to line breed my female and was wondering if it okay to breed a female to her uncle (fathers younger brother from a repeat mating)? Looking at the pedigree it would be like breeding her to father. The resulting COI would be 22.3%

  95. Sybil reynolds Says:

    I want to buy another lab pup from same place I bought my other one from . Mine is amale and want to buy a female . But is father to mine grandfather to other pup so what if they breed together

  96. Key Says:

    hi I have a male king corso and his mother and father just had a new liter. Is mating between the 2 a no no if I were to get a female which would be his siter from same sire and dam?

  97. Brenda Says:

    I have an AKC registered Havanese male dog, who is now 3 years of age. He came from our 1st litter of pups. We just had our 4th and what will be our last litter of 6 puppies, from our very healthy bitch and an unrelated, healthy sire. I was researching breeding our male 3 year old dog and a puppy from this litter, when she is of age to do so. They would be half siblings, both from the same Mother but different unrelated Fathers, going back 5 generations. We have not yet mated anyone with our male dog but we are planning to do so sometime in the future and trying to determine if we should simply buy a unrelated female to mate with him or if it was possible and recommended to keep a female from this litter and wait till she comes of age and then mate the two. Our male dog has some excellent traits within his breed. Good hair, size, no genetic problems, etc. The female from this litter of pups is too small to see what her traits will be like except that she will probably be a a good size and weight and her color is nice and she is healthy so far. Given when she matures with preferable traits as I expect she might, and when she comes of age to mate, would it be in your opinion to mate these two? Or would you suggest that we simply purchase another female to breed who is unrelated for past 5 generations back?

  98. Key Says:

    ok thank you. I’ve heard that it could be good to keeping the genes of them strong is that assumption wrong? what’s the negative side to this?

  99. davidcavill Says:

    Don’t – if there are problems is will exacerbate them

  100. Kari Ditty Says:

    I have a male Cairn terrier that has had all his tests done and clear, have the opportunity to purchase a bitch puppy that is a half sister…same mom different stud with all tests cleared. Male is almost finished with his championship and bitch well on her way. Would breeding these two be too close for line breeding?
    Thanks for your time!!

  101. AlyssaE Says:

    David, I have a very concerning question. I have a mixed breed in-bread dog. I got her spayed, so she cannot be breed. I though that was best for her. But my my concers are her future health. I know in a lot of dogs health problems don’t show up till the dog is older. My dog, is the result of a sir mating with his daughter. The sir was a Chihuahua/ Mini pin mix, the dam(which was the sirs daughter) was a Chihuahua/mini pin and Dachshund mix. The owners told me it was an accidental breeding. But know that my dog is almost 3 years old I’m concerned with wht kind of health risk she could face from not only being a mut but from being in-bread that closely. Any information or advice would help me out a lot. Thank you.

    • davidcavill Says:

      O think it unlikely you will have a problem because both were the result of mixed parentage. The difficulties we have with some pedigree breeds genetically is that they are mated closely withing their family for several generations and physically they are sometime extremes of type. Your dog does not have either of these problems in its background. So, although nthing is guaranteed in this world, you can stop worrying.

  102. Nick Castle Says:

    So this Saturday I am picking up my male cane corso. My dad and I thought of the possibility to breed in the future. My dad also thought about getting his corso from same breeder but a different dam that is due in 6 weeks. So pretty much, the sire would be the same but the dams would be from 2 different lineage. What do you think about this mate? Thanks

    • davidcavill Says:

      I know nothing about this breed (they have only just begun to appear in the UK). My advice is that unless you are an experienced breed always to go to other lines in any breed. It is not rocket science but there is no point in taking unnecessary risks

  103. Chantal Says:

    Hi David

    I have a female Alaskan Malamute. The breeder I got her from kept her sister. he then (mistakenly, he says) bred the sister to her own father. She had a litter of 10 puppies, all healthy. Can these pups develop health problems later on? I know he kept one female pup from the litter, that he plans to breed (however not to her own father anymore!!! Could he be breeding a dog with potential health issues?

    • davidcavill Says:

      These things happen and genetic health problems are always possible. It is a percentage game. They are less likely if parents are unrelated and more and more likely the closer related they are. But this does not mean problems are inevitable – just they they are more likely. And the breed makes a difference. A pair of closely related Malamutes are basically a very healthy breed so less likely to have a genetic defect than a pair of, say, Cavalier King Charles Spaniels where there are some problems which are embedded in the DNA. In this instance I would not be particularly concerned but would make sure that the next two generations of matings from this litter are from different lines.

  104. Steve Says:

    Hi David,
    Hopefully this question has not been asked, but I may have missed it. We are thinking about buying a Brittany puppy where the male dog is the bitch’s uncle. I guess that this is line-breeding rather than in-breeding, but do you feel that this relationship is too close and too recent?

  105. J'One Says:

    I’m thinking about breeding my Banddogge Stud (Jahsaree) to his daughter (Nyla) who’s mother (Remy) is also a Banddogge from a different family. Jahsaree is 8 years old and and Nyla will be 1 in November. Jah is in excellent shape no health issues what so ever, and his temperament is amazing. Please inform me on what to look for to have a successful inbreeding/line breeding experience.

  106. adrianna Says:

    Hi I was wondering if it is ok to breed aunt to nephew there pit bulls? Im getting a puppy who was bread like this and I want to make sure its not bad

    • davidcavill Says:

      IF only it were that simple. Aunt to nephew need not be a problem but if the line is already closely bred it could be. I would need much more information – and I still might not know the answer. IF we did know the answers we would all only breed perfect dogs

  107. Nicole Says:

    I have just placed a deposit on a female Golden Retriever Puppy and received her Pedigree Certificate with her heritage information. I am quite concerned as her parents both have the same sire which makes them half siblings. I will try and portray my worries with the rest of the breeding line too, as some other breeding patterns seem off to me. I am quite new to all of this but I am trying to educate myself.

    Brunnental Urban Blues

    Brunnental Jetsetter

    Brunnental Driving Force
    Brunnental Karshi

    Brunnental Driving Force
    Brunnental Volcanic Lass

    Great Grandparent:
    Brunnental Kardelle
    Brunnental Our Pleasure
    Brunnental Garbank Starturn
    Garbank Johnina At Brunnental

    Brunnental Kardelle
    Brunnental Our Pleasure
    Brunnental Urban Blues
    Brunnental Kalisko Lass

    Great Great Grandparents:
    Garbank Starturn
    Garbank Johnina At Brunnental
    Brunnental Farmers Boy
    Brunnental Jewel
    Ch Bethrob Bracken
    Garbank Oyez
    Ch/Ir Ch Garbank Special Edition of Lislone
    Nortonwood Miss of Garbank

    To be continued…

    • Nicole Says:

      Garbank Starturn
      Garbank Johnina At Brunnental
      Brunnental Farmers Boy
      Brunnental Jewel
      Brunnental Driving Force
      Brunnental Critical Air
      Brunnental Karshi

      To me, there are too many names that appear too often but as I said, I do not know much. Could you please advise me on whether I am right to be worried? Kind regards and thank you for providing such an informative report and your ongoing support. Nicole

    • davidcavill Says:

      It looks sensible line breeding but perhaps you should ask the breeder for the Coefficient of Inbreeding of the litter! You want it to be low – under 7 is good – over 12 be careful

  108. traci Says:

    This article did help me tremendously when I was worried about my 15 month old grand dogs they did mate but it wasn’t something we planned

  109. Mike brunning Says:

    Great site good solid information and we’ll writen article with out emotions

  110. Stuart Says:

    I have retrievers, I have been breeding the same line for 12 years, my bitch line has remained strong, I have 4 generations of my bitches all descended from my foundation bitch. I tend to breed cousin, half uncle to niece or outcross out every 2nd generation, so I have out crossed twice.
    My next mating will be mating uncle to niece, my bitch to her mother’s litter brother. I’ve delayed doing this mating until I was 100% happy with the line I have, my dogs have good hip scores and clear eyes, and are living well. I felt I had to build a line with all good results before I bred closer than I already had done. These 2 dogs are excellent match but I only feel confident as I know the lines, followed the health of all pups I’ve bred and know dogs in the pedigree as individuals not just as names on the pedigree document. The 2 I’m pairing have also had pups previously to unrelated dogs, I think important to see what can be produced from dogs you plan to breed closely.
    Just thought id share my experiences.

  111. Stuart Says:

    Hi David, thanks for the website, very informative. I think you’ve find a great job explaining it all and offering advice.
    My question is, a lot is said about prepotent stud dogs (dogs that produce their type regardless of their mate), in addition how common and important are prepotent bitches?
    Can many bitches be prepotent or is it because they are limited to 3 or 4 litters their true impact is unknown? Just something that interests me.
    One of my bitches had 4 litters, each to a different stud dog, 2 of the stud dogs she was related to, half uncle niece son the other a cousin. The other 2 were 100% outcrosses (to 5 generations) but her type was prominent in all her puppies, as pups bad into adulthood. Was I perhaps lucky all 4 dogs whether related to her or not matched her in physicality, or phenotype. Estentially a male version of her.
    Just a question. 🙂

    • davidcavill Says:

      In theory both sire and dam contribute equally but it is generally accepted that the characteristics of the one which is most homozygous is likely to have the greatest impact. So this would mean that bitches can certainly be prepotent. It is also often said that a kennel is founded on its bitches and this would indicate that experience confirms the observation because it is the females which tend to be kept for the next generation rather then dogs. I would be interested to know of any research which proves or disproves this commonly held view.

  112. sofija Says:

    Hi, we have a brother and sister Yorkie. Brother is mated with his sister, we did not want this. I do not know what to do with the puppies. I’m afraid thay will have problems.
    Thanks and best regards!

    • davidcavill Says:

      But they may not. Yorkies are a healthy breed and if they two are not already closely bred the puppies may be fine. Keep a close eye on them and do not hesitate to consult a vet if you have any concerns about their health. I hope you are lucky

  113. sameh Says:

    Thanks for the great article and related discussion, what about mating a GSD bitch to its grandfather who is a grand son of a great bloodline of larus von batu, a bloodline that I would like to maintain.

  114. sameh Says:

    Does the sir have more impact on the characteristics of the litter as they say? And why? And how do I make use of this

    • davidcavill Says:

      Its a complicated question. In theory both sire and dam contribute equally but it is generally accepted that the characteristics of the one which is most homozygous is likely to have the greatest impact. I would be interested to know of any research which proves or disproves this commonly held view

  115. sameh elmallah Says:

    Dear David,
    i am trying to line breed larus, got a female with larus in her 5 generations, made the mating outcome check with my male (grandson of larus) and i got this outcome :

    Linebreeding – 5 generations Inbreeding
    Occurrences Ancestor Wright’s Hardiman’s
    3 – 5 2X VA1 Larus von Batu 00.79% 04.15%

    is that a good trial or a too long shot?

  116. Laura Says:

    I have a great male he is 4%, I am breeding to his daughter who is 6%, whats going to be the % of offspring. I dont plan any more inbreeding with this lines,.I have had the main line for 5 generations. The prcd is A, body type in every generation is the same. OFA’s good. All lived from 10-14 years, no problems till right befor they died of old age. Temperment is perfect. Does there seem anything I may need to know ?

  117. davidcavill Says:

    You can continue to mate closely as long as you are SURE there are no underlying problems. The best advice is you breed closely is two generations close and then bring in a male or female unrelated

  118. Rachel Says:

    Hi David,
    I just got a 9month old miniature schnauzer and the lady I got her from had her half brother (same father different mothers with no other inbreed in the pedigree) and he locked with her one time, if she is pregnant she would be five weeks along. She is not showing but her teats are swollen. Her vet will not do a spay because she is to far along. My concern isn’t just if the puppy’s will be healthy but how will it effect her being so young? I plan to have a ultra sound done next week to find out for sure. Her vet said she is either in a false pregnancy or she is only having one, maybe two puppy’s and that she may not ever show if she only has one. I guess my question is, should I find a vet that will termanate and spay her now or will she and the pup/puppy’s be okay if we go through with the pregnancy?

    • davidcavill Says:

      If you want the puppies and can find homes for them I would go along with the pregnancy – they are basically a healthy breed – just take care in the future! She would not have come into season if she was not ready to have puppies (there is no evidence I know of which confirms that there is any problem mating at the first season).

  119. Mary Robinson Says:

    This article helped. I am thinking of breeding an uncle/niece, through the male line. The niece’s father and niece’s uncle were brothers with same mom and dad. I began with a Shi-Chi, whose mom was AKC 100% ShihTzu and whose dad was AKC 100% Chihuahua. The Shi-Chi bitch mated with a small Yorkshire Terrier, with a Pomeranian mix. Both males were born to them, separate litters. One male is my Uncle. The other male bred to a full Shih Tzu bitch (no paperwork/AKC). Their was a female bitch born to that litter, which is my Niece. Your opinions, Sir?

    • davidcavill Says:

      Once you get into cross bred dogs you have know idea what problems might emerge. There are specific problems with some pedigree breeds but the advantage is that, by and large, you know what they are and can avoid them whether you are are breeder or potential owner. One you have an almost entirely random genome you certainly are likely to have hybrid vigor but there will still be genetic problems (as there are in humans) but these will entirely unpredictable. I have already seen a number of reports of genetic difficulties with some of the established cross breeds such as cockerpoos so I am afraid I un able to offer any useful advice

  120. Michele Misurelli Gillis Says:


    I just wanted to commend you on a very well written article! I have been a breeder/owner/handler of two breeds for 20 plus years and know that it is a constant learning experience, so I appreciate your input very much! In the last 10 years I have gone to a toy breed of dog and I must say that it IS very different depending on the breed of dog you are working with-just as you said. With so many underlying health issues in the toy breeds we have to be so careful getting too close with line breeding and inbreeding is a scary thought with some of the threshold genes, like luxating petallas. Some breeders have the nerves of steel to do it, I just don’t so I stick with line breeding and then outcrossing.

    I especially liked the way you handled some of your responses to the questions asked to you by some; people who really have no business breeding dogs (or anything else for that matter)- I have to say, I don’t think I could have been as diplomatic as you were so kudos to you!

    I look forward to more great reads from you sir!

    Warm regards,
    Michele M.G.

  121. tina Says:

    can you breed a sister with the son of her brother?

  122. Kelly reardon Says:

    Hi david i have brother and sister saddleback pigs and want to breed them for purely meat can this be done ? Thanks kelly

    • davidcavill Says:

      I have no idea of how closely they are bred and know even less about pigs. But if you are only interested in the meat so they are going to be slaughter quite young I doubt there will be a problem.

      • Kelly reardon Says:

        Yes only breeding for meat and was thinking of getting a unrelated female to mate with our boy to sell piglets for pets , so thankyou so much for your reply david , have a great day . Kelly

  123. Lisa Says:

    Hi, I have two pitbulls, one male and one female. They are both registered, but the male dog is the females offspring. Somehow he got to het while she was on heat and now she is having puppies. Will they be considered inbreeds or linebreed puppies and will they be normal healthy pups with such close breeding(mother to son)

    • davidcavill Says:

      This is close inbreeding and not to be recommended. The pups may be fine – it depends how genetically healthy the parents are and I cannot know that. I would advise that you let go any of the pups which are weakly or poorly.

  124. Laura Says:

    HI, I have a female cattle dog. I know the personality of 6 generations back. Her Dad is Toby, AKC champion, he is a great dog, His grandfather was the nicest red male I have ever met. The dam of Toby is from a kennel that my one female is from, but not related, the female is Chyna. Chyna when bred to Arrow,(son of my first ACD) produced #5 acd in 2012. I bred Toby to Chyna, and have 2 pups 3 years old and 4 years old.I want to breed back dad to daughter. Physically they are perfect. mom and dad are PRCD A, OFA certified, mom had Baer test, both have full Dent. Temperment is perfect. One is 4% COI, the other is 5%. What concern would there be with this litter if bred?

    • davidcavill Says:

      You sound as if you know what you are doing although breeding that close is not recommended (indeed, the UK KC will not register puppies so closely bred). It is a risk but you could get lovely puppies alhtough I would try to go for a less in bred mating

  125. Chloe Beasley Says:

    Hi David, ive been asked by my 7 month old bitches breeder if I would like to breed her with her grandfather, would there be any deformitys or defects if I do when she is mature enough to become pregnant?

    • davidcavill Says:

      As always it depends on the breed and how sound the dogs are. Under most circumstances it is good line breeding. It is usual to wait until a second season

      • Chloe Beasley Says:

        Thankyou, she is a pedigree Cane Corso, theres only one line breeding time in her blood line and that was her great great grandfather to her 4 greats grandmother, shes just come into to her first season

  126. christine.farrell Says:

    my male jack Russell mated with his sister who is year older on day 20 of heat 2 weeks ago if she is pregnant will puppies be ok am not a breeder, have read so much intranet info, should I get her spayed this week.

    • davidcavill Says:

      I should have her spayed in any case if you do not breed and have a male in the house. Ask your vet straight away (they could give an injection to stop a pregnancy depending on the circumstances) but most do not spay during or close to a season. Pups may be fine – the risk depends on how closely they are themselves bred. The closer they are the greater the likelihood of problems.

  127. Cyndi Dietze Says:

    I have two Australian Shepard’s, the female is twice the weight of the male, she is also very alpha. She is ready to breed, will her size make it hard for him to breed? Also if so, how can I help?

  128. Phillip H. Says:

    Hey David,
    My male Brittany is great grandson to NFC AFC FC Dimond Hill Dan, grandson of AFC FC The Rock, son of AFC FC The Rock II. I am thinking of buying a female to breed with him. That puppy is great grandchild of NFC AFC FC Diamond Hill Dan, grandchild of Londeree’s Dimond Hill Dan, daughter of Londeree’s Pam. Diamond Hill Dan was the only dog in the world to win National Field Trials 3 times. Hall of fame dog as well. My male has perfect health, and makes absolutely perfect field trial dog. I want to own and breed from my own female. Would this new puppy be a problem? If not for health reasons then for sale reasons when I sell puppies? Neither dog has any other matches anywhere through 5 generations.

  129. chris wiggins Says:

    on Dec. 18th 2014 3:56 pm– Chloe Beasley asked if ok to breed her 7 month old bitch to her grandfather , when bitch is old enough to breed. and your reply………under most circumstances it is good line breeding. Then my question to you “Will AKC register litter ? “

    • davidcavill Says:

      I am based in the UK so cannot give a definitive answer – I see no reason why AKC would object. it is direct relationships which are of the most concern brother/sister (the closest inbreeding), mother/son, father/daughter (one step away), uncle/aunt to niece/nephew (three steps away). Further distance is generally referred to as line breeding BUT this is very much dependent on the number of close relatives which occur in the pedigree.

  130. sissy Says:

    I have a mother dog and her son got her pregnant.will she die?

  131. Hello, I just found out that my male dogs (Hercules), grandfather and great-grandmother are my female dogs (Athena and Luna) mother and father. So that means that the owners had breed mother and son, to get my females, but is it ok to breed the male and females? Also, would that make them related, and how closely related would they be?

  132. Lucinda hall Says:

    Can you help me? I have just brought a mini Maltese dog and cannot find a male to put with it except a pup who has the same fathers son to my’n? I have been told that its called line feeding so it’s fine? Need to know as soon as possible the answer as on the verge of buying today. Thank you. :))

    • davidcavill Says:

      You need a great deal of experience to breed toy dogs and as you clearly know little about it it my advice is not to do so. You need much more information if the process is not to end with you losing your bitch. Go to Amazon and get a copy of my book All About Mating Whelping and Weaning, read it and then research for a sire with the knowledge you gain from it.

  133. Tori Says:

    Hi David, I have a question I have champion Line Labs I have a new litter that I really love how they turned out I wasn’t planning on keeping a male but I had another Breeder suggest it, Only thing is The Female I have that would be only Female to breed him to has same grandparents on Dads side Completely so Technically My stud and my females Dad were Brothers. and then my female has also one same grandfather (so already a produce of line breeding) my male If I keep him has totally Different mother and lines on her side. Is that too many relatives in one pedigree? its almost like breeding niece and Nephew together in my opinion any advice would really appreciate it

  134. Ben Brunson Says:

    From what I gather from reading your blog and some of the reply’s, line breeding is okay as long as the dogs are sound and you don’t keep repeating the close line breeding. I am looking at breeding two German short hairs. They share the same father. The lines that the dogs come from have yet to show any disease or problems. If I can breed them, I would only do it once, then move to another line in the next generation. I’m just trying to preserve the line. From what I gather you don’t advise this close of line breeding, but if we must we can?–Thanks–

  135. Janet Says:

    Hello David. I have been reading your articles on inbreeding and line breeding. It’s a bit confusing but I think I get it. I would still like your view on a puppy I would like to purchase. She is a Boston Terrier. The mother has the same great grandparent and great great grandparent. I also found out that the father has the same great great grandparent as the female. Bostons are very hard to come by here in Alaska as most are interbreed mush more closely. I will not be breeding her but I do want a sound puppy. Thank you for any in put you can give.

    • davidcavill Says:

      It is difficult. Boston terriers tend to be quite closely bred in any case (CoI 11.3 in the UK). There is a tendency for them to have eye (cataract) problems in the UK but, of course, I cannot speak for the States. You could ask the breed for references from other puppies he/she has sold – are those buyers happy with his/her stock? It would be a reasonable question.

      • Janet Says:

        Thank you for your quick response. Although I have not talked directly with anyone who has purchased a puppy the breeder tells me she has one of the same Owners purchasing another and a Vet in the area is buying one as well. I guess I better ask more questions.

      • davidcavill Says:

        Reaseach is never wasted

  136. Brandon Butle Says:

    I am a registered NSDR breeder for Australian Shepherds. I have two studs and two bitches. My two studs are half brothers( same father). They are both Slash V bloodline. My females are unrelated(over 5 generations with no like ancestor) to my studs. I recently sold a red Merle female and she inquired about breeding her to my black tri stud(her uncle) when she comes of age. Any genetic concerns with that pairing?

    • davidcavill Says:

      Every breed is different and the genetic concerns of one breed are likely to be quite different from others. That said, the breeding you propose is quite close but I am afraid I do not know enough about Australian Shepherds to advise you. You need to talk to other experienced breeders

  137. jess Says:

    What about uncle to niece husky?
    Uncle and mom to niece are bro and sis..
    No health problems on either side?

    • davidcavill Says:

      This can work very well if you are sure of your stock (and they are not already closely bred) but remember that once is enough. Any puppies should be out crossed if bred from

  138. Angel Says:

    Is it a bad idea to buy an ABKC American bully puppy who’s parents are brother and sister? They said it was an accidental and it wasn’t planned. So this would be the first time the parents mated (brother and sister). I hope you respond I would really like an professional opinion.
    Thank you

    • davidcavill Says:

      I do not know. Mating brother and sister is not good practice but very experienced breeders sometimes feel it is a viable option. Inexperienced breeders may not know it narrows the gene pool to a damaging extend and such close mating can often result in the expression of genes which cause genetic disease or physical abnormalities. And it sometimes happens by accident. Sometimes there is no problem but, personally I would not take a chance without much more information about the temperament of the sire and dam and their pedigrees.

  139. robbie Says:

    I have a female great dane and her sister has had some puppies would you recommend me getting one of her pups to breed with my female it would be like my dogs nephew?

    • davidcavill Says:

      I would need to know much more about the background to be able to say yea for it is too close a mating unless you really know what you are doing. And what would be the point – go out to a good healthy stud dog so you do not have to worry

  140. curtis Says:

    I have English Bulldogs. Have the same father. Female is alergy free and has a high energy temperament.

    Male has minor skin problems with Mange which is a bit to be treated. Yeast has been an issue but that was by way of missed baths and general hygeNE which has been corrected.

    Male does not mount naturally but will lock and sniff constantly during her heat cycle.

    I have discussed IA with their Vet.

    Their grands are both from show lines with many acculades between them as well as a few prize winnings hough out each of their generational lines.

    Both have good temperament in general and soundness is great.

    So half siblings. Breed or not?

  141. vicky Says:

    Hi jst wondering we have a male japanese akita an are getting out feamale nxt month but jusT to be safe if they mate we have jst found out that that our feamales father is great uncle to our boy which makes them 2nd or third cousins is this safe for them ?

  142. TanMurt Says:

    I am looking at doing a mating which has the same dog appears on both sides at 3rd generation and and same dog on both sides at 4th generation. These 2 dogs are not related. Is being this far back okay?

  143. Rebecca Hill Says:

    Can i breed my two yorkies. They have the same mum but different dads?

  144. Terri Says:

    Hi Dave, We are trying to get our line breeding started. We have 2 females from the same litter. We purchased a male puppy with a different pedigree. They have had some beautiful litters. we have decided to expand our breeding. Would it be expectable to breed aunt and nephew?

    • davidcavill Says:

      So much depends on the breed and its underlying genetic health. If they are all physically and genetically healthy the relationship is good line breeding – but you have to look further back to make sure that you are not breeding too close in the long term. Good rule of thum is line breed for two generations and then outcross for one.

      • Terri Says:

        Our Samoyeds Genetics s are good and health is excellent. So do you think that if we kept a male from one of our female’s litter and a female from the other female’s litter that it would be safe to breed those two pups after the age of two? Would this be the two generations?

  145. Terri Dunn Says:

    We are new breeders of Samoyeds. (About 10 years.) My first 2 Samoyeds were not related. They bread and I kept 2 females. We sold our male and purchased another male. We have had litters from both females. A male was sold 2 1/2 years ago. The owners did not neutered him. Would it be alright to breed him back to Chello which is his aunt. There is no health or genetic problems. Out of this litter we were planning on keeping a male and female. Then out of Echo’s next litter also keeping a male and female in hopes that we could breed Echo’s male to Chello’s female and Chello’s male to Echo’s female. Would this be an execptable line breeding?

  146. William Says:

    I have a 1 yr old male long hair doxie & i’m not sure if he got hold of a 1 1/2 yr old female long hair doxie. They both have same mother but different father.

    Would that be a problem if they get together this one time?

    – William

  147. Ian Says:

    I have bred ferrets for years, mainly for working. This year I have got a silver pied ferret with unusual marking. How do I fix this pattern in other litters

  148. tammy Says:

    I have a male boston terrier and his sister from from a different litter, they have the same parents but the parents are not related at all. they are both very healthy they dont have the normal breathing or eye problems that alot of bostons have. I am not wanting to continue with breeding but would love to have a puppy off of them because they are tempermented great and are healthy. Is this a bad idea and would their be deformities

  149. karlie Says:

    Hi I have an English cocker spaniel bitch and would like her to have a litter she is a show line but I am not sure what sire to breed her with to keep the blood line going?

  150. KC Says:

    Great Information. Thank you.

  151. Emily Vasquez Says:

    So I’m buying a baby husky in about a month from my neighbor that their dogs had baby’s already and my friend that bought a husky from him already and he’s about 11 months now ? I was just curious because she wants to breed her dog with mine until she’s older, but their no from the same time they were born but they are from the same mother, would the baby puppies come out bad if we were to breed them together ?

  152. Becky white Says:

    I have been asked if my dog will be a stud for a bitch who is coming into season soon. My dogs grandfather and the bitches great grandfather are the same dog…. Is this too close to breed?

    • davidcavill Says:

      It should be not problem – but why would you? Once a dog has been used at stud he is usually muck more interested in biytches when they are in season. It is likely to be more trouble that it is worth

  153. Bill Says:

    My puppies parents are half brother/sister (they have the same father and different mothers), does this pose any issues?

    • davidcavill Says:

      It could but much depends on the breed and your experience. But why would you?

      • Bill Says:

        Why would I what? I have a new puppy, a female Havanese, I received the AKC cert stating that her parents had the same father (diff mother) making them half brother/sister. I was wondering if this posed any issues and is a accepted way of breeding?

      • davidcavill Says:

        Breed from this pair. I would sugest you go out at this stage to an unrelated dog for your bitch

  154. Tracy Says:

    In response to the Golden breeding to a doodle question, yes it can be done, and yes the offspring will shed more. Purebred to purebred (Golden to Poodle) is an F1 Doodle. A Doodle back to either purebred line is an F1b. A Doodle back to a Golden will produce less curly hair…more wavy…..and more shedding. A Doodle back to a Poodle produces less shedding and curlier hair. But would still be an F1b Doodle.

    • davidcavill Says:

      That is very helpful, Tracy. Thank you. I am pleased that there are those taking a sensible and scientific approach to deliberate cross breeding. I am not sure that such specific consequences though. Has enough research been done to be sure? Canine DNA is very flexible and although predictable in some ways is not usually so precise.

  155. Gary Says:

    I adopted a siberian husky that is the sister to my daughters male husky. I found out 5hat those 2 hooked up during her first cycle. Consequently, she delivered 4 healthy puppies while laying between my wife and I. After the shock we now don’t know what to expect. 3 males and 1 female that all appear normal and healthy. Anything you can tell us about what to expect?

  156. Laura Says:

    I have two puppies from different mothers and fathers, but they have same grandmother. What if they were together?

  157. marla Says:

    I’m planning on purchasing a presa Canario puppy. The breeder bred a son to mother. The son is very aggressive alert guard dog. The mother is less social and a bit shy. What type puppy should I expect to get from this breeding?

  158. Ellie Harp Says:

    My question to you is, I have a blue silver dapple and I want to breed her. But I’ve read horror stories about double dapples. Which other colors would be good to breed her with if my goal/hopes are for more dapples? I just want to make sure I have healthy puppies! Thanks.

  159. pascal Says:

    pls I need advice on how best to sustain my wotties line and traits. I got my wotties by crossing my Yorkshire terrier female with a male rotteweiller.
    what do I do to sustain my wotties line. do I cross brother to sister or brother to mother? pls advise

    • davidcavill Says:

      This seems a very strange combination. I do not know the answer. You have created what is called an F1 cross. to get (approximately the same – and there is no guarantee) you will need to exactly the same cross again. If you want to establish a specific ‘type’ you will need to breed very closely for several generations – not something I would advice.

  160. Level Says:

    fascinating article! I want to breed my 3year old yellow lab (champs on both sides, no health issues). I’m having difficulty finding a stud in my area that isn’t her father/grand/ or great grand father. All of them being a top dog in their breed in various years over the past decade. Would it be too close breeding her to great grandfather or would that be considered inline breeding and safe?

  161. Mary Says:

    I know you’re assessing the line breeding with pedigree dogs but would like advice on chinchillas if possible.
    I have a female whose grandparents and great grandparents on her mums side are the same as the grandparents and great grandparents on the mums side of the male I plan to put her to. They have no relationship on either fathers side. All pervious generations are healthy and still living. Is this mating ok? I plan to outcross any offspring with an unrelated animal. Also what would this relationship be called? Thanks

  162. Joan Says:

    Hi I have two female English mastiffs and a male. Is it okay to breed a puppy from each litter to the other. Also can you breed brother and sister together

    • davidcavill Says:

      Dear Joan,

      Please read the article. You should not breed a brother and sister together. And I do not know what the relationships are t=between your two females and the male but it does not seems sensible. IF youw ant to breed English Mastiffs you absolutely should talk to an expert in the breed.

  163. Cliff Says:

    Can you Breed a dog from a first litter siblin to a 2nd litter sibling same parents different litters

  164. liliana Says:

    What about Son and Mom?

  165. Elizabeth Says:

    Hi my name is Elizabeth. My husband & I have 2 golden retriever, the same dad but different mom. Can we breed them?

    • davidcavill Says:

      I wouldn’t. A very experienced breeder who really knew what they were doing might but my question would be ‘Why would you? THere are plenty of GRs around of good quality. It is perfectly possible that you would not have any problems but there is a risk – why take it?any

  166. Selso Valdez Says:

    Hello, last year on February 14th 2015 we bought a brother and sister Pitbulls (Lobo & Lucy). They both are up to date on all shots and are very active and healthy. Today Lucy had puppies unexpectedly. We had no clue she was pregnant. She has been very active and a loving dog. She had 10 puppies. And they all seem healthy, they are all eating. Lucy is fine and Did everything naturally what a dog would do. Will these puppies be ok? Will Lucy stay ok? What should we expect? Even what should we do?

    • davidcavill Says:

      These things happen and it may well be that the pups are fine (but I would have one of your dogs neutered! Very close mating can work perfectly well. It is not that they will necessarily be disastrous but that the closer the two dogs are bred the greater the risk that, if they have a genetic or physical problem this is much more likely to be embedded in the puppies and in future generations. Experienced breeders can mate closely – because they are experienced and know what they are doing. If you are not experienced is is best, if you want to breed a litter, to use a dog on your bitch which has as different a pedigree as possible.

  167. Terri Says:

    would it be okay to bread a female to a male that would essentially be a half nephew. Females father is males grandfather, different mothers all the way around.

    • davidcavill Says:

      This is a typical scenario for a line breeding but there are always two issues. the genetic closeness of the the dogs AND their overall health. You should be looking at both

  168. Peg Says:

    Would you feel this breeding would be ok? Someone just told me it was too close.

    • davidcavill Says:

      I would ask on what grounds they think it too close. The pedigree looks fine to me (subject to all the points about health and appropriate tests I have made in previous replies).

      • Peg Says:

        Thank you….All health clearances done…heart, eyes, hips, and more. Sire died at 13 1/2 of probably hemangioma. That’s what they are concerned about.

  169. davidcavill Says:

    13/12 seem perfectly reasonable to me. Average age for GR I would have said

  170. Raymond Says:

    I have two akc registered huskies. They both have the same great grand mother. Will I have a problem registering the puppies with akc????

  171. Michelle Says:

    Hi David, I’m looking at breeding my Golden Female to a Golden Male. There is one similarity in the 5 generation pedigree. The males great grandfather and females great great grandfather are the same dog. I’m VERY concerned about keeping her line as pure as I can should I be concerned about this? Thanks for your opinion!


  172. Nao Says:

    Hi there,
    I recently looked at some puppies to purchase, father is a yorkie/shih tzu and mother is a yorkie/shih tzu. What I learned is that it is a daddy daughter litter…should I be concerned about this purchase.

  173. Gwen Ledwith Says:

    I have a labardoodle named Hailey. Her brother (labardoodle ) mated with a poodle which produced another labardoodle. My mom got a puppy from that litter so in relation Hailey is his aunt. Can we breed that pup with Hailey?

  174. Shannon Says:

    My male and female german Shepard’s have same father. Males mother is also the daughter or females mother. Both dogs are healthy intelligent well tempered dogs. Are they safeto breed

  175. lori Says:

    hi i have a question…is it ok to breed my great dane female to her half brother?they have different moms, same dad..there is no other crossbreeding anywhere in their lines..

  176. David Norwood Says:

    What is “Breed Watch?” I googled it and only found watches made by the company “Breed.” Your help would be appreciated.

  177. Lillian Says:

    I am heavily considering breeding my stud to his half niece? She is the daughter of his half brother and a husky from a totally different line. My stud is exceptional. Both so beautiful and healthy. I want to decide before her next heat because if I decide not to breed my stud to her I will have him neutered. I am confident they will make amazing puppies, but as a breeder I have never ever linebred or inbred and I am paranoid about the stigma ingrained into me that they’ll have mutant pups. I have always outcrossed and I was planning to with this bitch but I can’t find another stud that compliments her. Our Huskies have the rare agouti coats and beautiful blended fur, they almost look wolf like. Do you think it is safe to breed them together?

    • davidcavill Says:

      You sound as though you have thought about this very carefully. Depending on the pedigree background the CoI is relatively low. It sounds as though it is a valid approach. There is nt doubt that mutants can be the product of several generations of inbreeding – but mutant can occur with an out cross. What you propose seems perfectly reasonable

  178. john Says:

    Can i breed my spaniels they are cousins

  179. Brandon Says:

    Hi David
    I have 2 German Shepherds that wasn’t planning to breed but it happened. ..they have same father different mother…my breeder who I bought both dogs from says it will be fine but just wanted your opinion. ..they are both very healthy and are working lines with alot of drive in them…will these pups be over the top with their drives?….do I have anything to worry about?

  180. Sean Motter Says:

    Hello David,

    I have a female Gordon Setter that I am thinking of breeding to her half brother (same father different mothers). Your thoughts?

    Thank you!


  181. E.a. Says:


    I apologize before hand if i confuse you or use the wrong terminology.

    I adopted 2 dogs because i didn’t want to separate them.
    They are Pit-oodles.
    Their Parents are pink nose white coat blue eye Pit Father and white Poodle Mother.
    My Dogs (Pit-oodles) Mated.
    Now their are 8 dogs who are 8 weeks old which would be considered 2nd generation Pit-oodles?
    They are running around playing eating, pooping, digging etc. and happy as can be.

    This is the first and last time i will breed. Was this okay to do?
    Ive spend lots of time reading but all this reading just confused me.

    Thank you for your time.

    • davidcavill Says:

      Not a good idea – please check to see if any of the puppies are deaf – out of eight, statistically, 2 might well be if they are carrying the parents are carrying the gene associated with pink noses and pure white coats. But they may all be fine. When they go to theri new homes it would sensible that they be neutered.

  182. E.a. Says:

    Hi! 😀 Thank you so much for your reply, I really do appreciate it.

    As I prepared to feed them this morning, I whisled… something I hadn’t done and their ears went back (maybe because they have long ears and are too heavy to lift up) 🙂 I was looking around to see their reaction as well as snapping my fingers behind them and… I am so grateful to say, they are all okay. They are not deaf.

    I will let the future owners know to neutered them.
    Thanks again.
    I will not sell the dogs. I only placed a $$ amount to see who was willing to pay. I will surprise them with a FREE Puppy :).

    Have a great day Sir.


  183. Victoria Says:

    Can I breed a half brother to a sister They share the same father, but different mothers.
    Thank you.

  184. I just bred my male to his full sisters daughter. Makes it his niece. What about breeding a female pup from them back to her father? If you say no then I won’t do it. It is as good of dogs as I have ever had. I am 61 years old. Thank you

    • davidcavill Says:

      You are going very close so I hope you know what you are doing. These matings can produce very good dogs but depending on the breed and how inbred their pedigree is you may be building up pro0blems in the future.

  185. Mimi Says:

    I have a male labrador retriever that I am offering for stud services. We found out after purchasing him that he was bred by close breeding (father and daughter) He is very healthy. I am planning to get OFA clearances. Should they come back with a good report, would it be fine to breed him? Thanks

    • davidcavill Says:

      Assuming that all your tests come back clear there is no reason not to use him but is must be to a bitch who is also clear and which has a pedigree that doe not contain any of the dogs or bitches in your dog’s pedigree.

      However, you should remember there is not guarantee that things will not go wrong – that dogs breeding for you!

  186. Rhonda Grijalva Says:

    Hi David,

    We have a registered male lab that we have bred twice with the same registered female. We took one of his pups from the first litter as the stud fee. Without deciding what we were going to do with her and not apparently not getting her fixed in time, she is now pregnant by her father. After reading your article and several questions and answers it sounds like this is obviously not the best thing that could have happened. If I read right, AKC will not register the litter due to this. Obviously what the vets office told me was not correct, so my question is, do I just give these pups away when they are old enough? Can they be sold as purebred even though they can’t ever be registered? I know that I need to inform anyone who takes a pup about the inbreeding so they are aware of potential issues and she will definitely be fixed ASAP after the litter is born, but if there is any other direction or information you could give me that I have not stated I would really appreciate it. Please don’t scold me too badly. I have done that myself. I really just didn’t make it a priority to get her fixed and now I have to deal with the results. Thank you for your time.

    • davidcavill Says:

      Thanks for your thoughtful and responsible message. Do not panic. I am busy today but will get back to you tomorrow

    • davidcavill Says:

      Much depends on the breed. They may be fine but they may not. You cannot tell. My advice is to take the bitch to your vet and have here neutered now and, in effect, abort the puppies. If you do not want to do this you will have to see what happens and take your vet’s advice. I am based in the UK but I understand the AKC have same sensible regulations about registration as we do here. If the puppies are OK they might make excellent pets but the advice should be to neuter them. Don’t feel bad about it. It happens all too often.

      • Rhonda Grijalva Says:


        Thank you for responding. We actually did toss the idea around about the neutering but our vet told us if we decided to go ahead with it that it would be quite spendy. They did tell us that unless there has been a lot of inbreeding going on within the lines and especially brother/sister, that we should be okay with this one litter. We do have one possibly two people who already want one so, I think we will go ahead and let her have the pups and tell those who take a puppy the circumstances and that the puppies should not be bred and get fixed right away. Knowing the temperament of all of the dogs involved they will make good pets.

        Have a great week~

      • David Cavill Says:

        Sounds sensible to me

  187. Sandra Says:

    My sister an I purchased two puppies of a same litter. The puppies have grown up together always having play dates. I went away for a month to visit my in laws over sea and left my female with my sister. when I came back home I noticed my puppy angel was acting different. I took her to the vet and they said that she pregnant. how will this effect the unborn puppies?

    • davidcavill Says:

      Much depends on the breed. They may be fine but they may not. You cannot tell. You should have had one of the pair neutered. In fact your vet could do it now and, in effect, abort the puppies. You will have to see what happens and take your vet’s advice.

  188. Sherrie Says:

    If I have granddaughter of a sire can I breed to a sire that has same sire but on the 4th generation?

  189. Sherrie Says:


  190. Katrina Edwards Says:

    i have a bitch i bred from and kept a bitch on the second litter different father i kept a dog the daughter i will outcross but i want to keep a bitch can i put this put to the dog i kept?

    • davidcavill Says:

      Sorry, Katrina. I cannot work out what you want to do. Just keep mind that it is usually better to move away from the bitches family than move towards it.

  191. Louise Says:

    We have a blue staffy bitch and would like to know if it is ok to breed her with her grandfather?

  192. Adriana Says:

    Can I breed my botch to her brother? They have the same father, but different mothers.
    The breed is Portuguese Water Dog

    • davidcavill Says:

      Please re-read the article. I would not

      • Rhonda Says:

        My Frend breed a wild cat geen wich alows genealogy cross overs naturally
        He breed a Savannha
        Wich is a serval cross domestic
        He breed mom to sun
        And sister to brother
        What he got was dubeled up wild geens
        One boy is huge like a serval
        And the other is a bit smaller with serval trates
        Now he and I are using the new male to my unrelated girls that are high serval
        F2 and f3 fems
        What I’m trying to figer out is what % of wild cat thease males have become
        Is it 50% 50%
        Of both
        Because mom to sun and sister to brother
        A f 5
        Breed to f4 mom
        And f5
        Breed to f5 sister
        Or dose it give the genolage of back werds
        Now the new babys are f3 from mom and f4 from sister in wild cat geens
        I all so herd that will be stronger in most of the off spring because the cats that are domestic were wild cat breeds long a go now this wakes up the geen pool agen make them more wild blood because of ansery
        Hello I’m trying to place them in the right f s of the new geen pool

      • davidcavill Says:

        I am really sorry but I have no idea because I do not know whether you mean a genuinely ‘wild’ cat or a feral domestic cat

  193. Ken Mann Says:

    Great article, I want to breed a litter of racing greyhounds, I was thinking of breeding a grand-daughter of the great westmead hawk to his son ? I know the son and his main fault was his size at 80lbs and lack of early pace so I have selected a small 54lbs bitch who has great early pace, I am hoping to reproduce a dog with the talent of his father but eliminate the bad traits, I would then introduce a complete outcross into the resulting litter for vigour, this is a 4-5 year plan, it sounds like a good plan but I still have serious reservations … the ancestor loss 6 generations is 24.6% … double coefficient 12 generation inbreeding is 36.42%… any thoughts would be greatly appreciated

    • davidcavill Says:

      You have thought this through carefully. There need not be a problem with close breeding if you know what you are doing. It sounds as though you do. Line/inbreeding is how we got the breeds we have. IT is not wrong, it is just that if lines are continuously bred too closely problems can arise

  194. Mari Says:

    here is the thing, breed is Bernese Mountain Dog, mother to be and father to be have same grandfather from male side. Should they be bred? Have good hips,elbows, very good examples of breed, show dogs, same type, and they have same breed type in pedigrees.
    thanks in advance

    • davidcavill Says:

      The probelm is that the pictures are almost all terrible and do not give any indication of their true conformation. My views are very clear and best expressed in this article on my website – Are German Shepherds really ‘Germanic’?

  195. Jom Says:

    i have a male chameleon son of an unrelated pair, in his clutch he is the only blue one i have bred him with unrelated female and i am planning to breed their daughter back to her blue father. will this be alright?

  196. Tammy Woods Says:

    I am looking for a female Westie. I currently have a male Westie. I have found one but have found out that my current male this the female puppy have the same dad but different moms. Is this okay or not? I might want to have 1 litter of puppies in the future so want to be safe in making my decision. Please advise. Thanks. Tammy

  197. Jenna Says:

    If my male chocolate labs grandmother is my female chocolate labs mother can they breed?

  198. Morgan Says:

    Question does inbreeding dogs result in making them retarded or deformed

  199. Rocky Orozco Says:

    I have a 6 year old Boston terrier/French bulldog mix and she got pregnant by her brother for the second time. Two weeks before getting her fixed. Will her pups have genetic defects if this is her second litter?

  200. Claire Webster Says:

    I have lined my bitch fir the first time today and the male dog got stuck for about 15 20 minutes dose this meam I have to line her anymore times with him

  201. tasi sparks Says:

    I have a brother and sister pug/bullies,they bred twice.the first litter she had 8 pups.The second litter she had 7 pups.Will there be any health issues with these puppies as they get older?.

  202. tasi sparks Says:

    if a brother dog got her sister pregnant,will their off springs get sick and die?

  203. moe Says:

    Can pigs that share the same father mate?

  204. Kirsty Says:

    I have two miniature dachshunds, same mother and father, but out of different litters, and the mother and father are unrelated, is it safe to breed this pair, both very healthy

    • davidcavill Says:

      They are full brother and sister even though they are from different litters – I would not and, in fact, would advise against it. As a rule of thumb, the more extreme the conformation thee more likely there are to be complications.

  205. Dina Tortorich Says:

    Please help!!
    I bought a min Schnauzer and fell in love with her and decided I wanted to breed her (just once or twice) so I bought a small male for that purpose. A year later I found out through getting their pedigree that they both have the same grandfather on BOTH SIDES, mother & father’s side. Both pups are health and I believe the breeder have strong lines. Would that make them double cousins?? (if that is even a term)
    One breeder told me they are too close to breed but she also wants me to go to her & pay a stud service.
    I’am hart broken to think that I can’t breed them.
    Please give me your advise. Thank you!!

    • davidcavill Says:

      On the face of it (I have not seen the pedigrees) there should be no reason not to mate them if they are both fit and healthy. Sounds good line breeding to me

  206. Dina Tortorich Says:

    Thank you for for quick response. I have been spending hours searching the internet reading everything I could find with no clear advice either way. I appreciate your time and advice 🙂

  207. davidcavill Says:

    No problem. It is what we do at the Animal Care College 🙂

  208. emily Says:

    I have a male pug and female pug both very healthy. I have just been informed that they are related! They are uncle and half niece,
    My boys mum had a litter with a different male which then one of those pups had a litter which is my girl pug. We would love our pugs to have pups so we could keep one or two to have a little family but very concerned on the fact they are related please help!

    • davidcavill Says:

      I would not. Pugs are lovely but they do have both genetic and physical defects which might well be worse in a closely related mating unless you are very experienced breeders. If you want to extend your Pug family go to another really good quality stud dog

  209. Melissa Perdue Says:

    I have a female Pitt. My sister in-law has her parents. She wants to breed my female with her male which would be her father. Is this dangerous for eather dogs or pups?

    • davidcavill Says:

      I would not. Close mating are occasionally desirable under specific circumstances but you really need to be a very experienced breeder. And why should you? There is no shortage of good quality PBTs which would provide a goo line.

      • Lori Wilson Says:

        I’m confused. Recently I inquired about the scenario of a dad and daughter standard poodle breeding. It was an accidental breeding as the female was supposed to be out of province for breeding…guess dad got to her first.

        So would you say I should avoid getting a pup from this litter? There has been no other inbreeding or line breeding, whichever you call it. Basically no family members have been bred together ever, as I said, this was an ‘oops’

        Thanks Lori

      • davidcavill Says:

        There are many very close matings in the wild and in companion animals which are perfectly satisfactory so id the pups are well and healthy there should be no problem. Difficulties arise when that scenario is repeated over several matings. This is when faults and defects can be embedded. So there may be a problem (becasue they are of the same breed) but if there really is no doubling up of the pedigrees it could be OK

      • Lori Wilson Says:

        And generally do reputable breeders still charge the same even for an ‘oops’ breeding. I see they haven’t posted it as an upcoming litter. Maybe they don’t want to advertise this accidental breeding. I just want to feel assured that the odds of having a puppy with ill effects due to mating with her dad are slim. As mentioned these are not puppy mill breeders and they have endless logs of who is related to who so they don’t line/in breed. It’s a family and they all have a role. One takes care of the logs and who breeds with who, others help with the socializing and early training, growing etc. I do appreciate your opinion. I have never had a standard before. Toy and miniature yes for years. Thanks for any input


      • Lori Wilson Says:


        So just want to inquire…if this is the second time dad and daughter got together does that increase the odds or do you mean if the pups bred within family lines? We will not be breeding the pup for sure. What types of issues might I be in for? Anything I should ask the breeder? Thanks


  210. davidcavill Says:

    There are no regulations – only ethical standards and codes of practice which are not enforceable. But would everyone agree with a regulations. I am afraid they would nor. It is buyer beware, I am afraid. But there are many good, dedicated breeders out there who have high standards. They are well worth looking for.

  211. Jennier Says:

    My concern is breeding brother and sister from different mothers. Mothers are no kin in pedigrees. Thanks for your help.

  212. Marlene Smith Says:

    I have Havanese I have a male and a female the mail is the Father the female is the daughter they have bread once and they were registered with AKC is it proper to do it again

    • davidcavill Says:

      I would not have done so in the first place and I am surprised the AKC registered the litter (the UK KC would not have done). This is something you should only do in exceptional circumstances and with a great deal of expereince

  213. Graham o donnell Says:

    Can I breed half brother too half sister they are both Belgian shepards from strong knpv bloodlines

  214. Lisa Says:

    Would it be an issue to breed a standard poodle male who’s sire is the grand sire of a female we are considering purchasing ? Thank you kindly, Lisa

    • davidcavill Says:

      Another one of the ‘all depends’ questions. If they are both healthy and been test for relevant genetic conditions (and are clear) it should not be a problem

  215. Carlo Knight Says:

    I’m breeding my American Pitbull Terrier with another American Pitbull Terrier I was wondering is it safe to breed the father with the daughters when they get old enough the mother and father are not related though

  216. Kourtney Castillo Says:

    Can i breed a male pup from my dogs grandmother but also same dad? I feel it is close but some one said it could be done.

  217. Jim Bridge Says:

    I imported a female Rottie pup out of a champion bloodline. My girl is very correct with Excellent OFA rating for hips and elbows, heart and eyes. I recently bred her back to her father, an impressive Rottie that is championed all across Europe. These are two very correct healthy dogs coming out of the Arzadon bloodline. I have followed the bloodline back into the 1920’s and it is champion after champion dog. I’d like your opinion on this upcoming litter.

    • davidcavill Says:

      You appear to know what you are doing – this is most important consideration. As a ch show judge of Rottweilers I would like to see pictures (

  218. Tamara Chambers Says:

    I have a white female toy schnauzer who I bred with a like sized Maltese. I also bought a male Maltese from this same sire for future breeding of Mauzers. It was her first litter, and she only conceived two pups. One was breach and died during delivery. The puppy is one of the smartest dogs I’ve ever had and I’m thinking of keeping her. Would it be feasible to breed her to my male Maltese who is her half brother? There is obviously no relation in common with her parents as they are different breeds.

    • davidcavill Says:

      it just shows that simply crossbreeding to pedigree dogs does not necessarily make life easy. Personally I have no problem with people doing so and some of the results are beautiful I would agree but when there is a range of 400 pedigree dogs are available with I can see little point. Knowingly genetic history of your sire and dam and making sure you make the best (both physically and genetically) with the best is the safest way forward, line breeding to ensure a wide genetic pool and good breed characteristics. I am delighted that you have ‘the smartest dog you have ever had) and I would certainly have no problem with you breeding her but why not find a male which is genetically further away: that is much more likely to allow you to breed reasonably sized litters and healthy puppies.

  219. akash Says:

    I have a bitch and a male both are from same mother but different father. Can i make them mate?

    • davidcavill Says:

      Well I would not unless you are a very experienced breeder and have a specific reason for so doing

    • davidcavill Says:

      Why would you? They could mate but I would certainly not do so unless you are a very experienced breeder of pedigree dogs and really knew what you were doing. The very fact that you have to ask the question almost certainly means it would be better not.

  220. Tammy Chambers Says:

    Thank you. If I keep her I will probably have her spayed. I don’t want her to go through unnecesary problems that you mention. She is listed for sale but I’m having a hard time letting her go. Maybe I shouldn’t breed at all. I love them too much! Lol

  221. Jeannette shennan Says:

    I’m looking to breed my with my cocker dog bitch. My dogs great grandfather and the sire’s grandfather that I’m considering have turned out to be the same dog. Is this okay? And is this still considered linebreeding. Thanks in advance.

    • davidcavill Says:

      it was quite close at the time and fortunately they do not appear to have been any downsides. Yes it would be line breeding although this depends on the bitch that you are intending to use. A good out cross would be good but you might well have something closer that will be suitable

  222. Dashmond Sylvester Says:

    I have 2 English bulldogs (boy and a girl) with same mom and dad. I believe my girl is pregnant by the brother. I’M taking them to the vet tomorrow, but if she is what should I do? I’M not comfortable with this situation

  223. Mike Says:

    I’m wanting to breed my dogs a they both act and characteristics are very close besides color but are father and daughter. I have the mother and I know the grandparents from both sides and they are all healthy dogs. What is your thoughts?

    • davidcavill Says:

      I would need to know a great deal more and much depends on your experience as a breeder. I would avoid such close matings unless you have a very good reason for so doing. Both dogs may appear healthy but you do not known whether they have any genetic problems. Generally it is not worth the risk

  224. stu Says:

    Can mother and son be mated, I need to keep my new lines gene pool tight to begin with, there is no line breeding either side for over 5 generations and both dogs are in tip top condition.

    • davidcavill Says:

      Of course they can be but why would you? If you have a very good reason then you are experienced breeder (and should you wish to register them your kennel club will allow it) then there is nothing to stop you.

      • stu Says:

        Hi, I have recently moved to Spain , I breed imperial shih tzus, I have 2 stunning bitches , one from America and the other from uk, there are no imperial shih tzus here and for me to get a male from Usa would be about 3000.00, not including shipping. I can get my girl mated with friends driving their stud from the Uk , and hope to keep a male which would then be used to start this new Spanish line, ok to be used for girl 2 as not related , and was sure it would be ok to use back to mum, your article is very interesting thank you for also just putting my mind at rest

  225. stu Says:

    I would be failing my breeding programme opting for the standard size shih Tzu.. which are over here obviously 🙂

  226. Joe Says:

    Hi, I have a fabregas dog and a fabregas girl both have different mothers both greyhounds .
    Question can I mate these two dogs with each other ?

    • davidcavill Says:

      Well they are half brother and sister so unless I was a very experienced greyhound breeder who wanted something specific from this line I would not. I wonder why would you? it is not as if there is a shortage of greyhounds.

  227. Randi Coffman Says:

    I’m curious… my aunts dog olde english bulldog is pregnant and the father of the soon to be litter of pups was the son. Although this was unintentional, honestly both mother and son (also father) are beautiful dogs with a beautiful build, colors, and personalities.
    The male is 3 and mother is 8. The breeding between the mother and the father of her son had no relations 5 generations back. The pups are almost due. Both dogs are very healthy with great temperament, no allergies, no cherry eye, no problem has presented itself so far as to joints or hips. After the pregnancy was discovered my aunt altered her male.. so that this wouldnt happen again. My question is I believe these could really be some beautiful puppies with great temperaments, and I am thinking about getting onenough of pups. Obviously there should be no line breeding with my puppy anywhere soon or near, but would the puppy be ok..

    • davidcavill Says:

      What you say it’s perfectly sound and the resulting puppies might be excellent. I would have them checked over by an experienced veterinary surgeon to make sure they have no obvious health programmes and, as you say I would not line breed from them. Have a problem in dogs is not the occasional very close breeding it is the way in which the cumulative effects of close breeding buildup genetic and physical anomalies which are not in the best interests of the dogs. And, of course, the extremes of breed type (such as Bulldogs) are the ones which will most quickly be affected so just take very great care

  228. Rose Says:

    I am part owner of a Chinese crested bitch the breeder of her wants me to breed her to a male 8mth old pup of hers I have both dog &bitch have same father I say no am i right I

    • davidcavill Says:

      I would agree with you. An experienced and knowledgeable breeder might do this once the male was mature but I would be very cautious. Chinese Crested are notoriously tricky and have very complex pedigrees.

  229. rose Says:

    thank you david now in process of returning bitch as i mated to 1 of my boys to give her litter back but she wants me to terminate the pregnancy at 35 days as she says she doesn’t like the dog . this has killed me and want to pack showing the cresteds

  230. Charlie Says:

    Hello I was going to breed American bandogs soon, they are American pitbull and neopolitan mastiff cross, I was going to take my female neo and breed her with 2 different male pitbulls and keep a male from one litter and females from the other and mate them together, will that be OK ?

    • davidcavill Says:

      I wouldn’t unless I was a very experienced breeded and knew what I was doing. I could ask – Why would you breed close when it is easyier and safer to breed out?

  231. Bruce Says:

    hello.. I have a West German working line male shepherd. I kept 2 of his daughters after the mother passed away. The mother was half american and half german shepherd no papers. I was told it would be ok to mate father and daughter to up the pups blood line. ( male has been x-rayed no joint problems ) . Only reason I’m asking is I really liked the special bond that grew between me and the mother as I helped her with her new borns.

  232. Bruce Says:

    Yes..I was told it’s a one time only. Thanks for the quick reply. If they do mate .. your more than welcome to a pup. They’re so smart

  233. Mary Says:

    I am going to ask a simple question. I have seen it asked here before, but each dog is an individual, and would like to know your opinion on my GSD’s. I have a Female, that I am breeding to a total different line of GSD. I have her 1/2 brother (Same father, their mothers are full sisters), which I am breeding to a total different line. My question is: Can I breed my female to this male (no inbreeding at all with them), keep a female, and breed her to my females 1/2 brother (Uncle to niece), to keep my lines, as they are amazing tracking dogs, without any issues? I know this is close, but there are no health issues with any of my dogs, hips and knees are good and no DM. I would like your honest opinion, on this breeding. Both my female and her 1/2 brother (3/4 brother if he is because their grandfather is the same sire, and their mothers are full sisters, not sure how you rated the relationship on this), are serious high drive working European lines, with superior tracking instincts. Please advise, I can give you their pedigree if you email me. Thank you for your time. Mary S

  234. Diane Hamilton Says:

    I have a very healthy brother & sister poodle & would love to mate them – is this far to risky. Their parents are not related.

    • davidcavill Says:

      That is very close line breeding as you move forward down the pedigree, Mary, but it sounds to me is if you know what you’re doing and that is the most important element of any decisions of this sort

      • Mary Says:

        Thank you David, This female was bred by her 1/2 brother on her first litter. It was a mistake, he tied with her. He got out, and I didn’t get to him fast enough, they are VERY FAST!
        She had 2 pups by him, both are extraordinary puppies (now 2 yr old with no issues. This breeding are similar, but would be the same sire, bred to the daughter. I love my lines, they are such good pups and adults. This female has many super litter puppies that have excelled. I don’t want to do any damage, but would like to bred her pup once to see how we do. There are no guarantees, but would you breed this pair?

    • davidcavill Says:

      There is always a risk in any mating and the close of the dogs are the greater the risk but if you have the test results from the parents and you have a good reason for making them then all you are doing is ‘taking a risk’. It is likely that there will be no problems unless you continue to mate closely further along the pedigree but there is a chance that there could be and you would have to take appropriate action which at best will be caring for a dog which was not fully fit or in worst case taking the decision to put put it to sleep. Such decisions have to be taken all the time of course it may be nothing to do with the close breeding.

  235. Mary Says:

    Thank you

  236. Jane Says:

    I was hope you could shed a little of your wisdom on a question for me.
    I own a samoyed bitch who I am planing on mating, her health tests are good her temperament is absolutely lovely. It has taken me a lot of debating to choose a male but the one I like the most would not be line breeding, it would be an outcross (a like to like match)
    What are the down sides of this ?
    Would I end up with puppys that held a look of them both ?
    I have done a lot of research into both pedigrees a like what his holds.
    Thank you for your time

    • davidcavill Says:

      Dear Jane,

      Go for it – is the dog has the characteristics that you want it is the sort of mating which could produce a flyer. My rule of thumb is the line breeding for two generations and then use and out across. If you can use and out cross which has the phenotype that you want (and and that will probably be the phenotype of the bitch too) that the likelihood is a good, healthy hybrid litter

  237. Ray Friedl Says:

    Just received my akc papers for my dog and noticed that his great grandmother is on both sides of his bloodline. Is this common or is this an issue that I should bring up to who I got him from?

  238. Bailey samuelson Says:

    I have to miniature aussies 5 years apart, they both had the same dad but different moms we had an oppsie and now she’s almost close to giving birth will the babies have issues? None of them have ever been inbred. This is the first time and by accident

  239. I have an Airedale puppy which I want to breed, her Aunt is going to have the puppies, I will be getting a male from this litter. Can I breed these two dogs? So I guess it would be her 2nd or 3 cousin? The female is only 9 months old right now and won’t be bred for another year. The fathers will be different. My puppy has the same father as the mother to be. Hope this isn’t too confusing.

  240. I have 2 Siberian husky sisters from same litter. I have purchased a male pom, an have pedigree up to 4 generations. My question is, if I breed these 2 females to this 1 male, can I keep male pup (nephew to 1 of girls) an breed my female (aunt) with him to get the traits I want. Example.. Luna is very unsure about everything, her sister is trusting, an runs to you if confused or scared. If I took a male pup that had the same “attitude” as the trusting sis, an breed it too the unsure female, could it push out some of the “unsure” trait.? ( Aunt &nephew). No medical conditions known. All are healthy . Just food sensitivity in girls.

    • davidcavill Says:

      Sorry, Belinda, I would not contemplate any of this. Both Siberians appear to have temperament issues (one ‘unsure of herself’ and running to you if ‘scared’ is not ‘trusting’). And what would a pom/sibe cross breed have to offer? It would probably look like a German Spitz. If you want a dog like that this is a breed which already fits the bill. I have no problem with cross breeding but this does not seem sensible or useful

      • Belinda Says:

        Thanks.. the reasons are personally. A husky off leash is known to b a lost dog. Where I live people buy huskies for looks not expecting the husky personality traits… 1st being running, second digging, an third is just to involved with play to come when called. So u have over flooded kennels of lost or unwanted huskies. However the pom is very personalble.. they want u to pay attention to them an stay by your side. Not to many poms have flight mode, even in playtime… stubborn, yes. But mostly wants to b with you. Trying to bring out best in both. Thanks for ur response.. I have been studying COI on my girls. Thanks again any any info is much appreciated

      • davidcavill Says:

        Belinda, I think you are still on a hiding to nothing. in my view your Siberians have serious behavioural problems: however much they love you there is no doubt that they are unstable. I would leave out of any breeding programme. There are so many misunderstandings about dog breeding and you can get into a dreadful coil trying to understand the technicalities of genetics and the COI. Keep it simple and if you want to breed go for exceptionally sound physical and mental stock

  241. Cindy Crump Says:

    I’m breeding miniature Australian shepherds. The dam is a blue Merle and the sire is a black tri. Their first litter resulted in a litter of 4 health pups, two black tri’s and 2 Merle’s. I am keenly aware that you NEVER breed two Merle’s together in this breed due to vision and hearing defects. However, my question would be is it safe for me to breed the black tri dad back to his Merle daughter or to his black tri daughter or neither. The dad’s temperament is fantastic and he is the smaller toy size of the miniature Aussies, a trait that I would like to pass on to future pups. Also would I be allowed to register their offspring if dad and daughter were registered? Thanks so much for the advice. I realize that I am not a “professional breeder” but how can I learn if those that do know won’t help to educate me? I have asked other “experts” online before, and their responses have always been along the lines that an expert breeder would know the answer to these questions. Again how can I know if no one will reveal this secret knowledge to me? I appreciate your advice very much!!!!

    • davidcavill Says:

      firstly Miniature Australian Shepherds are not recognised by the UK Kennel Club so you could not register them in this country. If you have papers suggesting they are registered you need to look at them very carefully. If they are registered they might just be very small and the breeder has implied that as they are registered they are fine for breeding. If both parents are registered, whatever the size, you can register them but it would not be very meaningful because as undersized Australian Shepherds they would not likely to do well at shows. Of course if you are in this States you can register them if both parents are registered. Going on to your question, personally I would not breed as closely as you suggest. Before going back to the first sire you need to have another layer of the pedigree by mating the offspring to and AKC registered out cross and then use the original sire. I suspect that the reason you have not had much help is that you are asking for advice about from those which assume that you will be competition to them. Be brave: breeding dogs is not rocket science but you do need a fair amount of common sense and always keep soundness and genetic health of the parents in mind.

  242. Belinda Says:

    Sorry, also.. “trusting”. I explained wrong..she is trusting with me.. belly rubs sleeps at feet, so on… it’s when treating her, medically… ( ear infection.. cold.. ). That she hesitates to determine how she wants to act.. an takes weeks for her to get over the fact I won each battle.. she was the alpha female in her litter. An proud of it. It’s like I crush her every time she is forced meds. Baths.. or nails.. because I’m gonna do it. An she still won’t come into bedroom until she for sure no baths. Or anything going in her mouth she doesn’t want. Thanks again

    • davidcavill Says:

      This just confirms what I have said in my previous response

      • Belinda Says:

        Thank you very much… I see now what you are saying.. If I resume.. its worth expense for a well adapted good health an body bloodline. Not to try an fix what is already broken. Thanks again. 😁

  243. davidcavill Says:

    Good for you, Belinda. I appreciate your comment

  244. Cole Vidrine Says:

    I got a Belgian Mailnois whose parents are from the same litter. He was a gift. He is everything I want in a dog. Strong prey drive, forgiving, comes immediately when you call him and is 110% out going. How is this looked upon and can he be registered? This dog has got it all going for him and would like to take him to his limits. i got first pick of litter and he was above and beyond the rest in prey drive. He does not stop. He is a bitting machine. His grandparents are from Belgium and are from a kennel out of Chile great blood line. This is the first time in lineage there has been inbreeding. What say you? I hope you have good to say. Cole

    • davidcavill Says:

      whether or not he can be registered will depend on what paperwork you have from the breeder and whether your kennel club are prepared to register dogs of such close breeding. A description of your dog as a ‘biting machine’ worries me. Why would you want a dog that bites the unless you are in the security business or services and he can be trained not to bite. Without sin the pedigree I have no idea how closely he is bred but either way it would appear that if you do what puppies of him you should choose about Crufts

  245. Jeffrey LUECHTEFELD Says:

    My aunt let a brother and sister teacup Chihuahua mate and have 8 pups, 7 lived. What chance is there that these dogs will not be very healthy.

    • davidcavill Says:

      Frankly, I am amazed if this is the case. And I would suggest that human sex of the fittest survived they are pretty healthy as arginine parents. There are no guarantees of course it sounds good so far.

  246. Gabrielle Says:

    I have a female shepherd, and am planning on getting a male shepherd soon. I recently discovered that the female’s grandmother is the same dog as the male’s great-grandmother. It is unknown whether they share any other dogs on their pedigrees, but I could find out. If that is the only one they share, and assuming they both pass all health tests, is it okay to breed them?

  247. Natasha Says:

    Hi, I am looking at buying a cavoodle (1st generation) where neither of the parents (father toy poodle and mother cavalier) have undergone PRA testing. The breeder has the cavalier’s mother and grandmother still and neirther have eyesight problems. Could it be possible that the cavalier could still be a carrier and pass this on to the cavoodle puppies?


    • davidcavill Says:

      If neither have been tested and both carriers the puppies will have PRA. The parents and grandparents may not have eyesight problems but will still be be carriers. You cannot tell unless they are tested. I would be careful and if you want to be sure insists that at least one of the owners of the Sire or Dam at their dog/bitch tested. If one is clear there will not be a problem except some of the puppies will be carriers and you should be aware of that if you want to breed.

  248. Natasha Says:

    Thanks for your help re the cavoodle / PRA testing question.

  249. leezom Says:

    Hey David, can you please give me an explanation on (1) whether I should breed my husky to her half brother that is, they share the same mother but, have different father. I’ve seen the stud and like my bitch they are both healthy. And (2) my bitch have eyes which are partially blue but the stud have plain brown eyes. Will the offspring have blue eyes, will they be healthy? Kindly help.

    • davidcavill Says:

      Is very close but the breed is generally healthy so it might be okay. My initial response is ‘why would you?’. There are plenty of good Siberians around so why take the risk?

      as far as I’m aware there are no health issues with the colour of Siberian Husky eyes. They can be any colour or even mixed colours in the same eye. I’m afraid I do not know what the genetic chances are of any offspring having brown eyes but the key thing is that it does not matter

  250. Amber Says:

    My cat got loose last night and she’s in heat and her dad is a stray cat all I knew about him that he was black and white and I think my baby girl mated with a black and white male yesterday I’m scared the kittens with be deformed. Do u know if father daughter breeding with her kittens be OK?

  251. Kathy Says:

    My male German shepherd got to his daughter. What will happen if I let her have the pups?

    • davidcavill Says:

      It all depends on the health of the parents. if they have no physical or genetic issues then it will probably be fine (you can never be absolutely sure) but if they are not physically and genetically sound then there could be problems

  252. Nikki Says:

    Hi im from SA and i have a question and need advice please… I have a silver dapple dachshund (mother solid brown+ dad silver dapple) i want to buy her a boyfriend now i found a beautiful solid chocolate dachshund BUT (his dad is a chocolate and cream dapple+ his mom a solid chocolate) please help me what is the chances for a double dabble… Thank you

    • davidcavill Says:

      I am afraid I have no idea. The genetics of Dachshunds are complex and I will have to consult someone who specialises in the breed. I will reply if and when I receive an answer from him

      I am grateful to my friend Ian Seath in helping with this reply, Nikki. He says: Regarding Dapple, the pattern is from a dominant gene. The only safe way to tell if the proposed “boyfriend” has Dapple is to get a colour DNA test done. It is possible that the dog may be chocolate Dapple and it’s sometimes hard to spot very light dappling. If it is indeed pure chocolate, then there is no risk.

  253. Jess Says:

    I’m getting 2 bulldogs American can I breed with them being the same litter

  254. Cora Henning Says:

    Hi David – I have yorkies and just had a litter of the most beautiful puppys the mother and father is not related at all and come from 2 different breeders – i am thinking of keeping the one chocolate female from the litter -My concern is keeping her could she then mate with her father when she is adult or will this cause a problem?
    Thanks Cora

    • davidcavill Says:

      Well, they could make if you are not careful but I would not advise such close breeding. The UK Kennel Club would not allow the puppies to be registered in any case but I do not know what the situation is in other parts of the world.

  255. shane Says:

    Hi David,
    I have two Jagd Terriers. Half siblings, same sire. The Dams are unrelated.

    Being good workers I am thinking of mating the half siblings. What are your thoughts?


  256. Roy Toal Says:

    When breeding for physical performance,
    In say lurchers (greyhound cross working dogs) inbreeding has a place ,but considering you start from two totally different breeds ,how close is too close, father to daughter,can fix traits quickly , would it be acceptable for 2 generations then out cross to an unrelated lurcher.

    • davidcavill Says:

      this is sound breeding practice

      • Roy Toal Says:

        Thanks for your reply David ,this is only theoretical at the moment ,and should better performing stock become available that would be used 1st .
        As I’d assume in breeding can’t improve what you have,only fix what you have and make more consistent.

  257. Joshua B. Says:


    My friend and business partner each own American Bullies and are passionate about the breed. We’ve entertained the idea for some time to start a kennel and breed Bullies. We are now at a point where the idea can become a reality and we have the financial means to make it happen.

    Currently we are putting together a foundation stock to start our kennel’s bloodline and breeding program. We each have a high quality female purchased from a very reputable breeder. The plan is to obtain outside stud services of the highest quality from a reputable breeder when the females are ready to mate. From each of our females’ litter, we hope to retain a quality male pup to be used within our breeding program. We then intend to breed each of our male pups to the others original female.

    Here is where my question comes in. Each of our females share some common ancestry. Each of our females share a common grandfather and his females grandmother is the same as my females great grandmother. To be even more specific, my female’s mother’s father is the same as his female’s father’s father; and, his female’s father’s mother is the same as my female’s mother’s mother’s mother. Now to reiterate, we intend to breed a male offspring from our respective females with each other’s female. So I would be breeding a male who’s great grandfather and great great grandmother are each the grandparents of his female on her fathers side.

    All dogs are of the highest quality and have some great ancestors within their bloodline/pedigree that we hope to maintain throughout our breeding program. Do you see this form of line breeding as an issue with the generational closeness and overlapping ancestry?

    Thanks for your help with this!


    • davidcavill Says:

      The important thing is that you are giving your breeding programme serious thought so even though there is some close matings of you are much more likely to be successful that if you were doing it off the cuff. What you are suggesting is not unreasonable but it is a bit close. Have you thought of working out the ratio of inbreeding just to make sure that you are not exceeding the guidelines.

  258. Teresa Says:

    I have a male staffy and there is a person that wants to breed their female staffy with him but the problem is that the females grandparents are my males parents help needed urgent

  259. Kristy osborne Says:

    I am looking at getting a male puppy to breed with my female. I just found out that the puppy’s grandfather is the same male that is my females dad. Is this far enough down the line?

  260. Momodu anthony Says:

    Pls am having an issue with my female dog, she won’t allow any other dog to mount her, except her brother from a different father, but same mother. Can I allow that? What are my chances if i allow same mother different father dogs to mate?

    • davidcavill Says:

      There is not enough information year for me to give you any sensible advice although it worries me that your bitch is setting the agenda rather than you. I’m sure there are temperament issues? much depends on the breeds in question and what the pedigree looks like beyond the initial parents. It is fairly open it should be no problem if your breed as any genetic issues you would be wise to avoid close matings

  261. Louise Says:

    Hi. I’ve been told that my german Shepard X labspin mix bitch could be bred with a German Shepard providing it’s a full breed, and the puppies would then be pedigree puppies, is this true please?
    Many thanks

  262. Hello,
    We are going to pick up our miniature dachshund in a couple days. Being relatively new to this (our first puppy), I thought I had all bases covered as they showed up the parents and everything seemed ok. Well, I ended up studying the pedigrees today (which I didn’t know before I could access and didn’t ask for it), and the puppy’s father is also the mother’s grandfather. I understand this is typically classified as Line breeding, correct? The father is not found anywhere else in the 5 generation pedigree. Is this something to be concerned about? I am suddenly extremely nervous and overwhelmed with all the information I am reading. Any insight would be greatly appreciated!!

    Thank you!

    • davidcavill Says:

      Hi Becky, You are quite right in thinking that this is acceptable line breeding and you are unlikely to any problem as a direct result of this combination. There are no guarantees of course, but if you have seen a puppy with its mother and on the premises of the breeder and you have assessed their condition and the environment as being acceptable (as well as developing relationship breeder) then all should be well. Good luck

  263. Jack Comeaux Says:

    My male father is Borack. The females Grandpaw on mothers side is Borack. Her great grandpaw in the fathers side is Borack. Can we mate thes two.

  264. andric Says:

    HI, If I breed one exelent hound with with his exelent daughter hound, could I make some good hound pupies in firt generation OR I just arhiv gens in that first generation pupies.
    Is it necesary to make one more breeding generation with that pupies and other hound to make exelent hound ?

  265. Beth Says:

    Hi, I have a 4 year old female Irish Terrier amd have just bought a male Irish terrier with a view to breed them. They are however Aunty and nephew (on the male terrier side). They are both pedigree dogs and registered with the KC. There are no health problems with either dog as far back as 5 generations and they have wonderful temperaments. Would you advise against breeding them due to the aunty/nephew relation? Your thoughts would be greatly appreciated. Thanks

  266. andric Says:

    I meen….if I archived excellent genes in first generation pupies, is it necesery to wateing secend generation with that pupies and other hound or I have chances
    to make exelent hound in first generation ?

  267. davidcavill Says:

    It doesn’t work like that. There are no guarantees you just have to do your best and hope that the best with the best possible stock

  268. andric Says:

    Ok thank you 🙂

  269. Missy story Says:

    If I take a puppy out of one litter and one out of another litter and the only kin is the daddy of one of the litter and the mom of the other litter are brother and sister would it be ok to breed a the puppy together out of the 2 litters

    • Missy story Says:

      I am ask this because there is a lady got a puppy from me and she is wanting another one to breed to the one she got from me and I wasn’t sure if it will be ok to breed them that kin me my self don’t like to breed them together when they are kin

    • davidcavill Says:

      you should make sure the parents of a puppy you sell her are not related to the parents of the puppy that she has already got

    • davidcavill Says:

      Might be OK with some breeds but always better to avoid close matings if you are not an experienced breeder

  270. Stuart Says:

    Are half brother to half sister matings still as common as they once were or are breeders avoiding these closed matings as we are now told a higher coi is bad?

  271. davidcavill Says:

    My gut feeling is that you are right but I have no statistics to prove that

    • Stuart Says:

      Personally I see very little wrong in a half sibling mating if you are aware of what you are doing. Often the coi % is lower than many other relationship matings.
      This train of thought that is being rammed at us from every direction that the lower the coi the better is not something I agree with.
      Sellers quote it in their adverts but I’ve a feeling very few know what it truly means and the general public rarely do either.

  272. davidcavill Says:

    I absolutely agree with you but would emphasise your point that you have to be aware of what you are doing. Like so many things COI percentage is merely a tool to provide some information and should be used along with extended pedigrees, assessment of the quality of parents and comparisons with puppies of very similar matings. Information combined with knowledge, commitment and research is what best provides quality puppies

  273. Melissia Pratt Says:

    I have a female Labradors. Her father is also her fathers grand father . If anyone could give me some input on this , I would greatly appreciate it .

  274. Lisa Boye Says:

    Hi. We are looking at getting another german shepard to breed with our female. The pup we are looking at may be the offspring of her step brother… is this worth looking into or a “no go !”

    • davidcavill Says:

      All other things being equal and they are both healthy dogs it seems to be a good example of line breeding but you probably want two out cross the next generation

  275. Heather Says:

    I have a miniature schnauzer I need to know the safer breeding route. The two mates currently available to me are either her second/third cousin They would share a grandfather. My girls grandfather on her fathers side, and the males great gradfather on the mothers side. The other mate would be a direct nephew from her half sister on the fathers side.

  276. Ashlee M Briggs Says:

    I currently have a standard female poodle named Adley. Her sire is Rudy. I am looking at a prospect male for breeding from the same breeder I acquired Adley from. The male pup in consideration, his mom is Bailey who is a previous daughter of Rudy, making her male pup the grandson of Rudy. Would there be any issues breeding a daughter to the grandson of the same Sire?

    Thank you

    • davidcavill Says:

      In theory this is a good example of line breeding but, as always, you should ensure both dogs are sound in wind and limb and that you have completed any tests for genetic problems which are available

  277. June Lucas Says:

    What about breeding daughter back to her father? Her parents are full Blooded YORKSHIRE TERRIER and not related….

    • davidcavill Says:

      Not impossible but you really should be an experienced breeder before you take this route – and if you were experienced I think you would not need to ask the question. 🙂

  278. Rhonda Wiggins Says:

    We just had our second litter of BOSTON TERRIER. Are you saying brother and sister from different litters can not be bred to each other.

    • davidcavill Says:

      puppies from different litters with the same parents are full bothers/sisters. It is not a recommended that they be mated and, indeed, many kennel clubs will not register the puppies

  279. Sabrina Bratton Says:

    Can I breed a female to a male if the female is the daughter of the male’s brother please text me answer at 8165581744

    • davidcavill Says:

      Your telephone number does not give me enough information to text you. In any case I would need a great deal more detail to be able to advise you. frankly, unless I were an experienced breeder in the breed you are in I would be very very cautious

  280. Robin Vogel Says:

    Can u plz tell me if I didn’t want it to happen and the puppy is still a puppy he is only 8months and he is trying and if I am not home and if it’s happens to I have to worry about anything to bad the puppies is her son and he is not a year yet what should I do I am going to get her fixed and I can’t keep them apart bc he will break and eat everything and jump out the window he had been here with her since he came out of her and it just start today and I think she is almost done with her period

  281. Kenneth Swanson Says:

    I have a havanese that had numerous health issues and died at age 9. After investigating further I found his maternal grandmother was also his parental grandmother. Would that be a result of poor inbreeding?

  282. Barbara Spilchuk Says:

    My girl, Sara, expressed Legg Calve Perthes Disease at 8 months of age and had an FHO at 1 year. She is in the OFA database. I have just learned that two of her 1/2 sisters from a different dam/same sire, also expressed LCPD and had FHOs within months of my girl. This made 3/9 puppies out of 3 bitches with the same sire that expressed LCPD. Should the breeder be continuing to breed that sire within a closed breeding pool?

  283. Andy Says:

    Hiya David can I breed my old thyme bulldog with is niece

  284. Emily Says:

    Hi I have a question… okay so I wanna mate my Chihuahua dog .. and the same lady I bought him from has more Chihuahuas and she’s gonna sell me a female but the only thing is that my dog and the female Chihuahua share the same mom but different father … Is it okay to mate them or no?

  285. David Guzman Says:

    Would breeding two Belgian Malinois who share the same father different mothers be too close of a line?

  286. Andre lopes Says:

    Hello i have a question…
    I Have 2 syberian both with LOP (portuguese origin book)…
    The female as 5.5 years old e the mske as almost 14 months… Cant i mate them and get the LOP for the babies?
    My only question is about the age of the male…
    Thank you very much
    And a prosper 2018
    Andre Lopes

  287. Erica Warren Says:

    Im curious as to if mating my bitch with the grandfather is a good choice . she has very similar good qualities that the grandfather put in the pool . im just curious as to if itd be an ok choice .

  288. We have a Labradoodle female cream wavy coat, appears to have no shedding and a Shepadoodle male that is black , silver down legs , white star on.chest, and some brown around his ears, beautiful soft wavy non shedding coat. They are a litter apart, from the same mom cream registered poodle. The Gernan Shepard male is a top notch registered, trained beautiful dog from German breeder sable.
    The Lab dad is an english lab, big square chest, beautiful cream.
    No health issues at all in background.

    Would letting them breed be ok?
    Anyone have idea on results.
    If we can have puppies anywhere as good as these two we have, we will be happy, as both aee great dogs.

    Thanks in advance for any help or info!

    • davidcavill Says:

      I am delighted you have two lovely dogs but I am afraid that I have no idea what the result would be if you mated them. Because they are a deliberate cross-bred the best thing to do would be to go back to the breeder and ask they would carry out the same or very similar mating again. It is possible that your dogs would ‘breed true’ but the experience of those who have ‘created’ breeds in the past (Dobermanns for instance) is that it takes s a long time and many trial matings

  289. Anita Hammett Says:

    I am purchasing two Maltese puppies, male and female. They have the same father and different mothers. SHOULD I breed them?

  290. Melissa Says:

    Ok I have a giant schnauzer who is expecting anyday. I have a buyer whom wants breeding rights for a female. We check the bloodline and my bitches grandfather which would be the puppies great grandfather is the potintial studs great grandfather. Is that far enough down the line to breed?

  291. Myra Says:

    Can puppies from brother sister be registered with AKC?

    • davidcavill Says:

      I am fairly sure they they cannot be – they certainly could not be registered in the UK – except under exceptional circumstances and then only with prior permission

      • Barbara Spilchuk Says:

        Sadly they can be. There are few breeding regulations in the CKC or the AKC.

  292. Dawn Malcolm Says:

    I have a blue merle male pup and the breeder I bought him from has a pregnant female that is the grandmother to my male. She was breed to an unrelated male blue merle. If I were to get a regular colored female pup from the litter to breed to my male is there a greater chance of double merles in the pups that would be produced from such a breeding?

  293. A Says:

    I bought two Doberman puppies told they were not related but upon seeing a larger pedigree I see that my male pups mothers fathers mother ( so i think this is my pups great grandma ) and my females mother is the same dam. So can i breed these two? I have tested for vwd (one is clear one is carrier) dcm ( both clear)and dm (both clear). These litters were three years apart. The only relative in common is this one dam. The dam was mated with a male to produce my males granddad. The dam mated three-four years later with a different male to produce my female.
    Thanks for advice

  294. vlad Says:

    Hi! I have a Weimaraner bitch. 6 yrs old, healthy. I want to breed her with a lad thats 3 years of age, also very healthy. They have 4 completely different parents, and grandparents. Should this be okay? Thanks!

    • davidcavill Says:

      Sounds good to me. 6 is quite old for a first litter so keep an eye on her as she comes to term in case the process stalls but this a breed which is usually fit, strong and healthy

  295. Kelly Says:

    What about breeding if they have the same grand parents on one side.

  296. Dennis Says:

    I have a male Pekingese his parents are not related. He is one year old. I am getting a female soon she has same father but diffrent mother who are not related. She is three litters apart from my male. Would it be ok to breed them if they have same father?

  297. Kelly Says:

    I’m thinking of breeding my bitch who’s grandfather is the same as my males father? Is this okay?

  298. davidcavill Says:

    Depends on the breed. Too close for some breeds but probably OK for others

  299. Suzie pantalani Says:

    I have been breeding bulldogs for over 10 years I do have a question..I have a male that is a product of a full brother x sister breeding that were linebred cut her back with out crosses.. I bred him to a unrelated female the pups are now 2 years old could I take a FemAle pup bAck to her dad? All have had genetics done an all dogs in question have champion titles I’ve never been able to read anything like this to know or have examples…I’m not a experiment breeder..would like to know the genetic possibilities to have a dog so tightly bred.. obviously those pups would never be bred to anything related but I have seen huge progress when line an inbreeding my dogs just don’t want to go to far

    • davidcavill Says:

      It sounds to me that you have given the matter a great deal of thought. I think a brother/sister mating is not to be contemplated lightly in any breed and I suggest that there are serious risked in breeds such as Bulldogs. But you appear to have been lucky. I would not push that luck and stay clear of close matings for two or three generations. The secret is to mate to a dog which has all the same physical characteristics but different genetic characteristics. ie: they come from different lines

      • Suzie pantalani Says:

        yes have given it a ton of thought both dogs are genetically clear an score high also have proven their selves in the show ring and agility. When asking a few repo vets I was told I could genetically create problems not shown in the lines. So it’s a defiant no go for me I appreciate your response..

  300. Martine Says:

    Both health tested and healthy Chows.
    The male’s grandma and the female’s mother are the same bitch. Is this fine to breed or too close?

    • davidcavill Says:

      About as close as you would want to go in Chows I think and there are some risks but it should be okay

      • Marcus Braggs Says:

        I have a husky and am going to breed with another friends husky but ultimately want to cut them out the equation after I have these beautiful pups. Now my thing is I don’t know the full history of his dog but it is healthy and mine has always been a wonderful speciman. I’d just want more dogs that look like mine and he has a couple traits in his dog that id like a female to inherit then pass to another litter. Would U say in this case is a good reason to inbreed?

      • davidcavill Says:

        Why not? It is the reason most small hobby breeder want a litter

  301. Brittany Says:

    I have a female aussiedoodle that was bred from a purebred standard poodle to a purebred standard aussie “black tri”, both are in great health, no health concerns. The black tri aussie was bred by my female aussie and my male aussie “red merle”. I am considering breeding the aussiedoodle produced back to my red merle male. so it would be the aussiedoodles fathers dad. All dogs are in great health and have had genetic testing done and are all clear on all tests.

  302. Jen Says:

    We are thinking about getting a puppy… When looking at the pedigree… the puppy we are considering has the mother’s grandmother and the father’s great grandmother as the same dog … Would this be a problem?

  303. Magen Pace Says:

    My 3 year old male pit has gotten my 1 1/2 year old female pit, which is his daughter, pregnant and now I have a liter of 7 puppies! This was NOT an intentional bred. Should I be concerned? Will there be problems?

    The mother of my 1 1/2 year old pit that just deliveres puppies is in no relation to the father.

    • davidcavill Says:

      This mating could be fine or there could be problems depending on the background of the sire. How do the puppies develop? If they are fit and healthy they can be homed – perhaps with advice they they should be neutered when they are mature

  304. Rachel W Says:

    Wouldn’t the inbreeding coefficient for a sibling mating be F=0.25, the same as for a parent-offspring mating?

  305. Lauren Says:

    My neighbor got his first dogs: pitbull siblings. He bred the male to the female (against my suggestions) in the female’s first heat. Then, he kept a female from that litter and plans to breed her to the male, her sire. I’m sure this too, will be in the daughter’s first heat. He says he loves his dogs, but he treats them like livestock: he sells the puppies. What can he expect out of such a litter?

    • davidcavill Says:

      Unfortunately there are few laws against this specific behaviour although in some countries this person would be offending under animal welfare legislation. He may be lucky – but outcomes are impossible to predict. Probably, the number of puppies in litters will get smaller and the puppies themselves get smaller too. He might also have an increasing number which are deformed. It does not sound to me as though he has the best interests of his dogs at heart

  306. John Wilson Says:

    My male’s grandparents are my female’s parents. They bred and had 11 puppies. both my male and female have amazing characteristics, color and temperament and are health. (They had DNA health tests)

    is this ok?

    • davidcavill Says:

      As always there is often no problem with close line breeding so long as the sire and dam are healthy both physically and genetically. The important thing is not to keep breeding too closely so it would probably be unwise for any of these puppies to be mated back into the same lines while they are likely to produce healthy puppies if they are then mated to an hour across

  307. Kiki Says:

    Considering a Standard Poodle puppy and when looking at the Dam’s pedigree and saw that the Dam’s Sire was bred to his mother. Breeding a mother and son seems wrong to me. Also this litter only produced two puppies and most of the litters I have seen of standards have many more dogs. Would you skip this puppy?

    • davidcavill Says:

      Yes. Such a mating is generally to be avoided but poodles are a pretty healthy breed and there is no doubt that an experienced breeder could he do so. Many Kennel Clubs now no longer as allow such matings to be registered. Much depends on the site and the dam of the puppies although you are right that 2 is quite a small litter for a Standard Poodle. Ask that they be health checked by an independent vet

      • Kiki Says:

        Thanks for your response, David. The breeder said that mating happened by accident, but the dogs turned out fine. We have decided to wait for a breeder we have more confidence in. Thanks for this information site!

  308. Johnathan Says:

    Good evening sir, I wish to breed a stable hybrid between a GSD and Great Pyrenese. I plan to start with four completely genetic different parents all AKC. I’m going for coat\mask, behavioural traits and size.I genuinely care for my dogs health and don’t want a miserable dog that was forced into existence. I am very emotionally invested with this project and understand the difficulties of the end goal. The main question, is this a diverse enough gene pool? Or will I need to add more sires and dams? To my understanding line breeding is going to play a major role. Thanks for any insight in advance.

    • davidcavill Says:

      Sorry for the delay in my reply and I have been away. I appreciate all that you say and I think the way in which you are approaching this project is correct. I would say that it was certainly a diverse enough gene pool given that both the GSD and the Great Pyrenees are themselves healthy. The only question I would ask is ‘why would you?’ I’m not suggesting that the project is not feasible but however successfully these the establishment of a new breed is extraordinarily difficult and of course if you are to keep to type you will inevitably have to use other examples of each breed which will eventually bring in their own problems. I would also ask whether there is not already an established breed which has the characteristics you are looking for. It might be better to start there. Just random thoughts. D

  309. Yeng Says:

    We have uncle and niece shi tzu mix of yorki and poodle. Would it be ok to breed?

  310. Bhb Says:

    good day, I have an American bully & I’m planning to breed mother and son mating.

    Is it okay? and if I do mate them what are the issue the might occur.. thanks,

    • davidcavill Says:

      The very fact that you need to ask suggests you are not an experienced breeder so I certainly would not. It mnay be fine but the closer the mating the more likely it is that physical and innate genetic problems will apear

  311. AGH Says:

    Good afternoon! I am looking at a bitch to pair with my male. The grandfather (dam’s side) of the bitch I am considering is my dog’s father. I am in Dachshunds, is this too close?

  312. Rebecca Says:

    Would mating an Aunt to a nephew related only by the Dad/Grandpa be okay in AKC Siberian huskies?

  313. Kim Says:

    Ok so for a long time when i was a kid, my family raise Dalmatians and Doberman Pinschers and bread mother’s with son’s and dad’s with daughter’s and they never had any problems with the pups just perfect dogs and here recently my 1st cousin Huskies mated together… They had 2 pups are healthy and beautiful but i don’t see anything wrong with the babies.. So I’m not sure if that was bad or not considering me growing up with the family mating the Dalmatians and Doberman Pinschers so close together?

    • davidcavill Says:

      If you go through my previous comments you will see I make it clear that if you are an experienced breeder so that you know what you are doing you can make quite closely. I believe that the current restrictions on very close matings by kennel clubs around the world are a mistake but there is no doubt that if you breed closely you are more likely to see genetic problems in litters. If you breed from very good stock then this is often not a problem but unless you are experienced it is probably a wise to avoid close matings

      • Kim Says:

        Ok thank you, I was just unsure cause I found out the my male’s mom and my female husky has different dads but same mother so I guess that would mean the same in close breeding cause of them having the same mother just different dads ..

  314. Cedrick Says:

    How about breeding grandfather to granddaughter dachshund? Is it okay?

  315. lisa Says:

    Hi David,

    I have been reading through your article and the comments. I am looking at breeding my aussie shepherd bitch to my male at home but I am concerned about them being too close.
    The dogs Grandfather (on his sires side), is the brother to my bitches sire.
    Would you consider this to be ok?

    Thank you.

  316. punachick Says:

    I mated my Chihuahua, very healthy with a friend’s Chihuahua I picked a beautiful female for stud fee. accidentally he wiggled ou of his kennel I put him in when she’s in estrus. he impregnated his daughter and the pups wete just perfect. they had 2 litters since but I’m retiring her, I’m wondering if I could mate the origional male with a female from a different litter of theirs. the 1st bitch was made by an unrelated female but he’s been mating with his daughter with no problems. if I retire her and he mates with a female that’s more than half him, the daughter of the father-daughter litters would it be safe or would it grow wings.. lol

    • davidcavill Says:

      In nature very close matings are not unusual in fact for many species they are the norm. They work because any weaknesses in offspring are deleted because those offspring do not survive. As far as domestic dogs are concerned if the parents are absolutely sound then very close matings may not do any damage at least in the first generation. If this ever happens it is important to make away from the previous parents in the next and succeeding generations in case a hidden genetic defect has become established. Whatever happens none of your dogs are likely to grow wings. I hope this helps

  317. Lara Says:

    I have a male Wirehaired Pointing Griffon. I found a female but it turns out their mothers are sisters from the same litter. Should breeding be avoided here?

  318. Rex Thompson Says:

    I have a male rottweiler and he has a sister that was born six months earlier than my male . His sister was bred to another male rottie total different gene pool having a litter of pups.
    Could I breed my male to one of those pups out of that litter. I guess they would be considered a uncle and niece.

  319. Vanessa Says:

    Hello David! Thank you very much for sharing this useful information. I have read through much of the thread comments back to 2015, and I don’t see an exact scenario match to answer my question. Forgive me if this is a redundant inquiry, but since I received my puppy’s pedigree, I’ve been a bit concerned about the genetic proximity of his grandparents. Allow me to explain.

    My puppy’s maternal grandfather is the same (GCHS CH) dog as my puppy’s paternal great grandfather.

    I’ve tried to wrap my head around the relationship between my puppy’s parents, but it makes my head ache. Can you help me understand if this is a healthy breeding combination? or could my puppy be at risk based on his genetic composition? Your guidance on this will be sincerely appreciated.

    • davidcavill Says:

      Relax. I do not know the breed but any genetic problem is very unlikely

      • Vanessa Says:

        Thank you David. Whew!

        My puppy is a shih Tzu, he is a pet and he will not be bred. His health is all that matters to me. Thank you for the great information, and for the reassurance.

        The reference to genetic coefficient was super helpful too. I watched the video and did the math. The solution = peace of mind.

        Thank you again.

  320. Albert Rodriquez Says:

    I have Rottweilers and the Dad or the Brother accidentally mated with my Female Rottweiler which is the Dad’s Daughter and the Brothers Sister. I don’t know which one mated with her as I wasn’t home and didn’t know she was in Heat. Will the pups then come out Deformed or mean in any way? Thanks for your insight

    • davidcavill Says:

      It might be fine – it depends on how closely related the parent and grandparents are. In the UK and perhaps in other countries, you would not be able to register the puppies but they may be perfectly healthy

  321. Kate Bellah Says:

    We would like to breed my daughters show heifer to her nephew. Im not sure if thats to close. What do you think?

    • davidcavill Says:

      I know nothing about breeding cattle but I understand that they often more closely bred than dogs. As always, it depeneds on how close the other relatives are over several generations. You should ask a cattle breeder

      • Ogi Says:

        Both dogs were examined for VWF (Von Willebrand factor) – everything is great, hips, elbows and eyes – all with best marks…
        Should I do anything else? Or just let the dogs do their thing? 🙂

  322. Eva Says:

    Hi david,

    Im a bullmastiff breeder in the philippines. I have 3 related females from same litter. A fur parent who got a female from the same litter wanted to buy a dog which is the son of her litter mate. Will this be okay to breed? (Personally I dont breed related dogs and bitches). Thanks.

  323. Ogi Says:

    Hello, David!
    I have female Standard Poodle and have found male for her, but
    his father and her Great grandfather (on her mother’s side) is the same dog.
    Is it ok, should I expect any problem?
    Both dogs are 100% healthy

  324. davidcavill Says:

    You seem to have done everything necessary. Good luck

  325. Carrie Averill Says:

    I would like to breed a dog to a brother from my first litter 3 years old to a female of a upcoming litter eventually , who has same father different mothers. Would this be ok ? Breed is Toy Australian Shepherd

    • davidcavill Says:

      I would have to have a lot more information Carrie. My view would always be if in doubt, don’t. But if you are developing a breed this is something that may be in your best interests

  326. Sherry Fauscett Says:

    Dear David,
    I have beautiful Spanish Mastiff pup breed from sound champion lines and was about to purchase a female pup from a very reputable breeder and noticed as I looked over the pedigrees that the great grandfather of my male is also the grandfather of my female. Will this be a problem if I chose to breed them? That is the only common ancestry I see. The parents of both dogs have good hips. Thank you.

  327. Jeannie Taylor Says:

    I have a male whose daddy is the grandfather
    To the female that I want to breed . Is that a doable breeding? Or should I not breed them together?

  328. Caroline Tallett Says:

    I am looking to potentially breed my bitch with her
    Second cousin. (Her mother is the great aunt of the stud).
    Would this combo be ok?

  329. davidcavill Says:

    I doubt there will be any problem there, then. D


    What are the risks related to mating cousins with clear health checks?

  331. cengle1992 Says:

    Ok dont know if this makes sence or not but they grandpa to my 2 females was matted to a dog thats not related to my females so if I got a make puppy out of that litter it would make it their half uncle would this be a safe match or to close and yes they are 100% healthy.

  332. Angela Allen Says:

    Would it be beneficial to breed purebred Great Pyrenees if bitch’s maternal father is same as male’s maternal grandfather? Bitch is DM carrier, male clear. Both have clear/good OFA hips, elbows, patella, thyroid, cardiac and NDG. Temperaments in both are favorable.

  333. Alex Says:

    Websites dont work

    • davidcavill Says:

      Thnaks for pointing that out. I am afraid things change over the years and this was posted over 10 years ago. May I suggest you search on Google for ‘working our co-efficient of inbreeding’ which should bring up the current pages and in the meantime I will research too and edit the post. D

  334. Sonia Floyd Says:

    Can I Breed my Male German Shepard to his Daughter

    • davidcavill Says:

      The short answer is ‘No’. Father/daughter : mother/son matings do take place mostly as mis-matings. Very, very experienced and knowledgable breeders and researchers may carry such matings out deliberately but it is definitely not recommended- especially in a breed where many have embedded genetic and conformational problems.

  335. Gavin Says:

    My Staffordshire bull terrier is in season and I have just found her and her son from a previous litter tied together how bad and high would the risks be for defects and disorders in pups she may have if it turns out she is pregnant ?

    • davidcavill Says:

      If they are KC registered you will not be allowed to register the puppies . However, if it has only just happened I would ask your Vet to chemically terminate the pregnancy. It would have been better to have avoided the situation but Staffies are generally sound physically and mentally so with luck they should be OK.

  336. Kaylee Says:

    I have an 2yr. old Sheepadoodle, that per my veterinarian advice is waiting till after a couple heat cycles to be spayed. Covid happened so her appt. has been prolonged. She was due to come into heat this month but it has yet to happen, that I have noticed. So to get to the point, my 8yr.old grandson left her out to potty and my neighbors had a 7mo. Golden retriever visiting. I have been told they spent quite some time together. No one witness anything, but what if??? I’ve been trying to read up and I guessing he is capable even though he is young. Unless her health or the health of the puppies would be in jeopardy, I don’t think I could abort. Any advise would be appreciated.

    • davidcavill Says:

      If you think you can successfully re-home the puppies I should just wait and see. They are likely to be healthy but no one can predict quite what they will look like although the size should medium


    I have a 5 year old Labrador retriever bitch
    The dog I am thinking of using as a sire ,his mother is a sibling of my bitches father .would appreciate your advice .

  338. Xp Says:

    Found a Barbet owner that will be having an accidental litter. Father to daughter. 4 dogs all very affectionate but VERY excitable and not trained with new house visitors. Nice family but will I be inheriting health and temperament issues?

    • davidcavill Says:

      I think you have answered your own question_ do you want an excitable dog. You should ask whether the parent shave been tested for Progressive Rod Cone Degeneration (PRA). If they have and they are clear the pups will probably be fine – if excitable.

      • Xavier Says:

        I don’t want an excited/hyper dog. I’m conflicted these unwanted personality traits in the parents caused more by their socialization and pack behavior versus genetic predisposition. Can negative genetic traits caused by breeding son/daughter be corrected by positive early stage socialization with my family? I suppose that by the 8/10 week age the pup may have already learned the traits I’d like him to not inherit. Barbets are very rare breed to observe in our area so we are unsure how to proceed. I will definitely ask the breeder about PRA. Thanks for your time and expertise!

      • davidcavill Says:

        You are asking a very complicated question. Good socialisation is vital but how much it would modify behaviour under these circumstances no one can know. You seem to be approaching the whole sensibly so I think you should have the confidence to make up your own mind. Whatever I say or whatever my opinion could all too easily be wrong.

  339. Maxine Lineberry Says:

    Is it typically safe then to breed dogs who would be 2nd cousins? The grandma to one is the great grandma to the other.

    • davidcavill Says:

      It would not normally be a problem – but if a pedigree dog it does depend on the breed. Check with the KC website for the breed to see whether any recommended tests should be carried out

  340. grisbrook Says:

    hi I’m thinking of buying a bitch from a litter to breed with my male but he would be her grand daughter. He is DNA tested and so is the mother and sire of the litters. They are long hair dachshunds. Would normally avoid it but I’m struggling to find breeders

    • davidcavill Says:

      Under normal circumstances this would be good line breeding but with any of the breeds with extreme conformations it is wise to ask for a specialist opinion. I would contact Ian Seath ( with details of the pedigrees involved and follow his advice

      • grisbrook Says:

        Awesome thank you. Also my dogs aren’t kennel or show dogs for pedigree? Does that matter ? We’ve just done generic testing for the breed

  341. davidcavill Says:

    No matter – Ian will be pleased to help

  342. Ru Says:

    Hello, I am currently looking for a Chihuahua pup. I have read that breeding two blue parents should be avoided. Is this the case with a KC blue and white sire and KC blue and tan dam. Some breeders say its ok, some say avoid. I understand this blue recessive gene increases the risk for alopecia, can this appear later in the bloodline, if this pup from two blue parents had her own litter with a non blue say? and are there particular colours in this breed that should not be put with in a mating? I am interested in this subject and really want to learn more. its very hard to find the right pup. Thank you for your time

  343. Janette Cosgrove Says:

    Hi there,
    Me and my family have been considering getting a puppy for sometime and we have recently been asked to be put on the waiting list for a new litter of Cavapoo puppies. My daughter has been questioning the breeding process and it’s come to my attention that the stud dog (miniature poodle) that is being bred to produce the litter of puppies is actually the father of the bitch who is producing this litter. I would be grateful for your thoughts as this is not a subject I am knowledgeable in. Many Thanks, Janette

  344. Laura Crossland Says:

    Hi ,can I breed my bitch with her grandfather? Shes a Staffordshire bull terrier

  345. Sarah Says:

    Can you breed an uncle to step niece?
    Breed Siberian Husky
    Health testing on both sides for 2 to 3 generations

  346. Gus Says:

    Any comments on breeding a uncle to a half niece. Working line German Shepherd Breed. Only related dog is grandfather to the bitch, dad to the stud.

  347. christal dennis Says:

    If my girl yorkie is 37% yorkie and my boy is 100% yorkie and they are not related. What percentage of yorkie will their litter be of yorkie.

  348. Concerned breeder Says:

    One of my female St. Bernards just mated with her son. We did not do this intentionally, but it is what it is, can’t be undone and now she is pregnant. This will be her third litter.
    This was her first heat since her second litter only 5 months ago. She was not showing regular signs of heat and up to this point (she is 3 &1/2 yrs) her heat cycle’s were consistently 7 months apart.
    1. As we intentionally don’t breed our females more than once a year, what extra measures, if any, do I need to take to make sure she is strong enough to deliver 10 or more pups a second time in only 7 months?
    2. Will the closeness in genetics cause any problems for mom during the birthing process?

    • davidcavill Says:

      Not recommended but accidents happen. If you are in the UK you will not be allowed to register the litter but there is evidence that if bitches are mated season on season their litters become smaller so I would not think that this would be a problem. I cannot comment on the genetic aspect as I do not know enough about the breed but if both dog and bitch are healthy and she has whelped normally previously I would not expect any difficulties. Good luck

  349. Jade Says:

    Hi I have a french bulldog and I have just bought one of his brothers bitches would I be ok to bread the them together or would this be too close in blood line?


  350. Hi, I have a female Aussie, her half sister had a litter. Out of that litter, a male was bred with an unrelated female and had another male. I’m assuming great half nephew to my female? Is this acceptable? All dogs are health tested

  351. Parris Says:

    Hi,what about two cousins

  352. K. Peter Says:

    Can we mate a great nephew goat to an aunt or to it’s grandma? Or to its second cousins?

  353. Ken Ocean Says:

    I have American Bullys , I’d like to kno if it is ok to breed the Uncle to the Niece ? The Niece has a Non-related Father. Thanks in Advance

  354. Sabra Sandee Says:

    Very informative..Thank you!

  355. Mj Says:

    Can you mate first cousins together?

  356. Pat Says:

    I have line bred father, Ivan z Hrdinneho Odvahy II to his Daughter Anna z Maxhaus 3 times now. The results have been strong healthy puppies with good temperament and some very tall going 100 pounds, but most around 75-85 pounds. German Shepherd Working lines. The father sire was Czech Police and his dam from Slovak Police breeding. The daughters dam is from Czech and West German titled lines with the sire being World Champion Schutzhund. Any thoughts? Puppies seem great, but many don’t like the father/daughter idea.

    • davidcavill Says:

      You clearly have two very healthy dogs and it sounds as though you are a serious and knowledgeable breeder. You know what you are doing but my article was ‘A beginners guide …’ and such combinations can be a disastrous. This is why many kennel clubs will not usually register such close combinations. Frankly, I think they are wrong but they are under huge pressure from lobby groups both at home and internationally.

  357. Gage parkison Says:

    I have a female lab, whose great-grandfather is my male labs father. That’s the only relation. All the females and rest of family line was different. We only found this out after we had purchased the female lab and looked at her family tree. Would there be any problem in mating them? Thank you in advance for any reply/explanation

  358. Ella Knapp Says:

    Can I breed a female with grandfather and great grandfather that has the same as
    the male 5th gen grandfather?
    I am planning on breeding them

  359. Mel Says:

    I have a female mastiff/ Great Pyrenees.
    Been looking for the about the same mix.
    Found male pup of her mother’s sister and of same father. If I get him, do I need to keep them apart when she comes in heat?

  360. Matt Says:

    Hi David

    We have 2 Rhodesian Ridgebacks (both sound in temperament and health) that we are considering breeding. They have had the RR bundle genetic testing done at Laboklin and they are both clear of all three genetic tests performed for their breed. They have had their hips and elbows tested and we are still awaiting results with BVA although were told when scored they both had excellent scores. Both have higher than average COI scores one at 15.7 & 15.5 breed average 7.4 and their puppies score would be 17.7. Both have same grandfather and on dam side he was the great-grandfather (not sure on sire side as only have 3 generations to go on. Could we ask for your thoughts on breeding them?

    • davidcavill Says:

      You seem to be doing all the right things. It sounds like sensible line breeding to me

      • emily65d Says:

        Hi David I was hoping you could help me, I’ve been a breeder for 15 years and have always used unrelated parents (as unrelated as you can), however I have been wondering if breeding a female to one of her grandfather’s would have any negative affects. In doing so I would be eliminating DM and CEA in the puppies – they would be genetically clear for everything – whilst tryibg to harness an incredible temperament. Is this too close?

      • davidcavill Says:

        It seems you are taking a very sensible and pragmatic approach. Of course, nothing is certain but this looks sensible yo me

      • emily65d Says:

        I should also mention they are rough collies.

  361. Jason Says:

    Would this be bad if I bred a male and female EB top quality lines no health problems,
    But males dad is females grandfather?

  362. I have a Male and Female GSD not related and are working lines in the pedigree…I have bred the same Male and Female for 3 litters now…I doing the hips and elbows on the Male which the vet said looks good…I will be doing the same for the female in late May…I will also be doing the Heath testing time make sure they clear all the dieases…my question is one of the pups front he second litter the owner has done the health test with Embark and the COI was 28%…so how is it possible for this pup able to have 28% COI of both parents when both parents are unrelated…I do have a half brother to the female but he doesn’t even be around her when mating is going on…is it possible the test could be wrong somehow…is this going to be a problem for the person to bred the dog later on…

    • davidcavill Says:

      Unfortunately, COI and ‘genetic heritage’ are not directly related. When you make a decision about mating a dog and bitch you are dealing with generalizations and there can be a wide disparity between what you would expect and what actually happens. And they may be unrelated but they could still have quite a close relationship within a breed

      • I know the COI and the genetics are totally different…I was more less saying how could both parents of the offspring have the same 28% COI and the parents are totally unrelated…no names on either side of the pedigree anywhere match…I just wondering if the test could be wrong or miscalculated 

        Sent from Yahoo Mail on Android

  363. davidcavill Says:

    I am afraid I simply do not know. It does seem odd – but then, much of dog breeding is about experience and instinct rather than science and testing

    • It puzzles me cause I cant see a offspring having the same coi as both parents…when thre are 2 different parents…the only way for that to happen is they have to be siblings or half siblings mating to get 25% or higher…I have read if the highter the COI you get better consistency and potency in the litters…I’m just wondering if the tests results could be wrong unless there was breeding between close relation on the dam side down the pedigree…my question was being the COI is on the higher end is it going to hurt to breed the dog with another unrelated female to bring that COI down in the litter if the person chooses 2… Thanks 

      Sent from Yahoo Mail on Android

  364. davidcavill Says:

    I do know the answer. You ask many questions but anything I suggest will be entirely speculative, I suggest the old fashioned approach. You are obviously experienced – go with your gut instinct. In dog breeding it is all to easy to ‘overthink’.

  365. davidcavill Says:

    No problem – when I have a moment I will do so more research and write about it

  366. Alana Halverson Says:

    I got my dogg fixed but my bitch went into heat a
    nd now her tits are getting bigger im just concer ed that she pregnant

  367. anniebishop1 Says:

    Is it ok to mate a bitch to a dog if her grandfather is the dogs dad . They are cockers

  368. Laura Super Says:

    How many generations in Bengal cats is it considered inbreeding? I found out my new litter of kittens. Their great-great-grandmother on both sire and dam site is the same.

    • davidcavill Says:

      It is not about the number of generations’ it is about the ‘Coefficient of Inbreeding’ (CoI). The relationship you have discovered would not be considered ‘inbreeding’ although, by definition all ‘breeds’ are inbred to some extent which is why they are recognizable as ‘the breed’. The calculation of the COI can be complex once you get beyond the first generation but in your instance it does not seem anything to be concerned about

  369. Karen Moxon Says:

    Hi I have litter sisters and one of them has had puppies if I were to keep a boy could he mate the other sister or is this too closely related. Both dna health tested clear. Many thanks

  370. James Says:

    So I have a male xl bully his sister had puppies from another male different blood line that male pup off that littler was breed to another female with a different blood line. Can I breed my male to one of those females of that litter safely?

  371. Heather Says:

    Hello. We have one male and two female AKC malamutes. Our male mother and father are the females grandmother and grandfather. The other side of the line has no related blood. Is this to close?

    So it is Uncle and Nieces.