HI Everyone

This is purely hypothetical but it is driving me nuts so would be pleased to be put out of my misery!!!

If a bitch and a dog were mated who were brother and sister what would happen? Is it like humans where genetic problems could arise etc.

Do dogs have to be unrelated to be mated (thinking of line breeding)?

Sorry if this sounds really thick but i've been looking up pedigrees and have totally confused myself!!! :)

Well I would never mate a brother and sister full stop ! Yes, you do run the risk of deformed pups/health problems etc with an incestuous mating such as this.
For health reasons, i prefer to outcross rather than line breed.(although you have to know what you are doing !) Line breeding is by definition (I think, please correct me if I am wrong here) when the parents share at least three common ancestors in a five gen pedigree.
I do feel that a lot of the breed related health issues have come about due to breeders line breeding too closely ... although no-one I know would ever consider mating brother/sister. Puppy farmers probably do though, because they don't give a damn.

Hi Zoe's mum,

>Yes, you do run the risk of deformed pups/health problems etc with an incestuous mating such as this

A bit extreme - and there is no "incestuous" mating in animals .......   While it would be ill-advised for anyone not knowing the absolute integrity of the lines they are dealing with to carry out any very close mating, it is - when done knowledgably - a way of bringing out the best!  Yes, it will also stamp the "worst" heavily into the progeny also but if the faults are minor and definitely do not compromise health, character or the most desirable breed points, then it is a good match. 

If you continually outcross (which is totally impossible anyway in some breeds) then every single mating is a gamble ;) 

Regards, Teri 

Well maybe incestous was a strong word to use. But no reputable breeder would purposely mate a brother and a sister. It is asking for trouble.
In my breed health problems are such that it does seem outcrossing may well be the safest and most responsible option. Cavalier king Charles Spaniel, before you ask lol. I think to very closely line breed is more of a gamble than to knowledgeably outcross. Just my opinion though.

Hi again ZM :)

I can fully understand why in some breeds with a major health problem that hasn't been identified into clear/carrier etc it would be folly to double up on a line but thankfully many breeds are not so aflicted and line breeding (occasionally close-up) is the best way to ensure good health, character and type.

I don't think closely related dogs should be mated without the breeder having in-depth knowledge not only of the coupling but also of their immediate relatives and ancestors (as Val has posted ;) ) but there is IMO a very strong argument for it being looked at in certain breeds and within specific lines in those breeds.  I don't personally know of anyone who has carried out a brother x sister mating, but know of several successful matings between half-siblings. 

One of my favourite dogs in my own breed is the result of a father x daughter mating and his type was clearly stamped on all his subsequent progeny as was the case with his litter brother who is on the Continent and I am proud to say I have one of his sons :)

Regards, Teri

As in all forms of breeding, the important thing is to really know the health and temperament of as many ancestors (both the dogs in the pedigree and their siblings too) as possible.  Close breeding doesn't 'invent' problems, but it does magnify whatever faults and virtues are already being carried in the genes.

Outcrossing involves even more genes in the pool, so knowledge of the dogs involved is equally as important.

Thanks for the replies so far. :)

Let me give you a hypothectical question if you don't mind -

If you had a bitch who had a particular fault that you wanted to breed out could you use a direct relative ie brother, father, grandfather? who didn't posess the fault or would you use someone completely unrelated? Is this a personal preference ie some would use a relative as they would 'know' the line and others would you use an unrelated dog to try and ensure the fault was bred out?

Thanks

It's important to know the lines which ever way you breed.  You cannot assume that because you outcross, that the same fault that you are trying to breed out, isn't behind one of the ancestors.

When people say "I've checked the pedigree and they are compatible", what they often actually mean is 'I've checked the pedigree and they do not have the same relatives'.  These comments show just how little they understand about genetics and modes of inheritance.

A puppy will inherit whatever genes the parents are carrying, whether they are related or not.  In depth knowledge of each and every one of the dogs in the pedigrees is enormously important if happy healthy puppies are to be produced.

Thanks Val,

This is something that really interests me after reading my dogs pedigrees, and i finally feel 'i'm getting it'!!

I take my hat off to the breeders who do it properly - i for one am far too lazy for all the hard work involved!!! :)

I know of a respected borzoi (and irish wolfhound) breeder who mated a litter sister and brother together. I'm not recommending it or condoning it but the resulting puppies done well in this country and in the States and were without a doubt of obvious quality and type. So clearly this can be done successfully :)

As Cavies are one of the most common breeds how often have they been so closely bred?  Is it not because people have gone out so much not knowing whether they'd be suitable that some of the problems have happened?

I don't know, just asking a question as I find this subject really interesting.

Half brother, half sister is not too bad if one line was different, but I'd never, personally breed full brothers and sisters, though there again I haven't done half sister/brother either but know people who have and they've had no problems.

I know a very good breeder who did a brother to sister mating although they were full brother and sister they were from different litters.  All the puppies were perfect and full hearing.  The son of this mating has been best of breed three times at crufts and is a outstanding example of the breed.  I have used him twice and only had on uni lateral puppy which is a exceptionally good result.  The puppies I recently had from him were outstanding.  I chose him for Molly because they are very closely related and both are identical types.  The puppies were exact replicas of their parents.

Yes it is a risk but then I have known people who outcross who have also had a appalling results both health and hearing wise.  As long as you know and trust the breeder and they are willing to admit to their dogs shortfalls and potential health problems then I dont see a big problem.  The problem arises when people do not admit that their are certain problems in their lines and you do not find out until afterwards which is why you have to wholeheartedly trust the stud dog owner and vice versa.  Unfortunately breeding in both humans and animals is a minefield.

A friend of mine had accidentally bred the mother and her son , 3 puppys died off the bat , 1 had 6 toes , 1 blind and only one healthy puppy.

This seems extremely unlucky...and I would also look to other reasons for this disastrous outcome. I know of many parent/offspring matings and have never heard of anything like this, but then I've never heard of a single blind puppy or 6 toed puppy in my breed.

I personally feel safer with outcross matings but have closely linebred in the past with excellent results. As another breeder mentioned, there is no such thing as incest with animals. It is sometimes difficult to separate our "human" emotions and feelings when dealing with animals though and I think that breeding brother/sister, father/daughter etc. commonly evokes negative thoughts for most people. We have to remember though that each purebred dog breed that we all enjoy today is thanks to close linebreedings and inbreedings to fix the traits we love. When done correctly (with enough knowledge) it is the best and safest way to breed. I think it is probably a lot safer to stay in your own lines when you know what genes you are dealing with rather than roll the dice with every breeding. At least with linebreeding you are working with the same faults or problems and doubling up on genes that you know about but when you outcross you are adding completely unknown genes to the mix and could double up on really bad ones at any time.

As for the bitch who was bred to her son and had only one healthy puppy in a litter of six, I wouldn't be breeding that bitch to any dog in the future... she seems to carry far too many damaging genes.

I read all of the above with interest.  I have miniature wire-haired dachshunds and am a fan of outcrossing in order to avoid fixing any problems in.  However, it is noticeable that the puppies from say, mating one of my show bred bitches to my German working lines dog, are definitely bigger than my line bred or closer bred ones.  Also, the outcrosses to the German lines are much more intelligent and have a much keener hunting instinct.  They are harder to live with as they are so full of it.  Because our weight limit in the showring is 11 lbs (5kgs) I always end up having to come back in to bring the size down and then go out again to keep the hunting instinct.  Have never gone closer than uncle and niece though.

I have outcrossed - mainly because in my breed there is a genetic illness with unknown mode of inheritence. The main problem with outcrossing is that you tend to get a very "mixed" litter, some very like mother and some very like father. BUT with careful research of ancestors, it is possible to see what is strongly "fixed" in both sire and dam. You do, however need to be brutally honest with yourself over what definite improvements you are looking for, and also accept that certain things will have to be left to improve on later - it is no "quick fix".

I don't know if this is true but I had heard that the KC permits father to daughter matings but not mother to son.  Is this true or just another breeding myth?

Another breeding myth!! ;)

I know someone who totally outcrossed and got one with a megaoesophagus, three with a heart complaint and one deaf puppy.  From the litter the line bred all were healthy with the same bitch.  If the genes arent compatable then I personally dont believe it makes any difference whether you line breed, inbreed or outcross.  Look how many perfectly normal humans produce children with disabilities even though nobody in their family has any of the problems.

I have owned 3 pups in the last 6 years which were brother to sister mating. One pup was a terrier breed, the other 2 were working cockers. I did not breed any of them but bought them in. Not one had any problems. All these pups were accidental matings but, on the basis that a gene is either there or it isnt and none of these pups had health or temperamant probs, I have used the sire of the cocker pups twice at stud as I was as sure as I could be that there was nothing nasty lurking as I took the view that if there was, then out of the brother to sister pups he sired, then at least one of them would have shown a fault in due course. Of course these pups had their faults, what dog doesnt, but nothing important to their quality of life or working ability . The terrier pup was shown and successfully too. However, none of these pups were bred on from - the terrier died in tragic circumstances young, and with the cocker pups I felt they would not benefit the gene pool to breed on from.

Totally agree with you TTS.  I've mated a dog and had nothing but problems, used a totally different dog and everything was fine.  Used the same stud with another bitch and they were fine.  Just felt that the two together just weren't compatible.