I have a beautiful four-and-a-half-year-old white Miniature Schnauzer. Her coat is what they consider a mega coat, very thick, she produces beautiful puppies. There have been no health issues whatsoever in the bloodline. I've had two different males from different parts of the country and are not related in any form. Have been tested for heart disease and knee disease, and there is nothing in the bloodline. I have one son from one male, one daughter from the other male. They're all white, if I mate the half brother and sister will the puppies be okay? None of the adults are related.

So they are both from the same mother??

I have an import pup from a half sister x half brother mating but her breeder has a bitch line going back 30 years and knows her lines. I am planning a total outcross mating to her. It can be done but only if you know what you are doing.

This is a mating that the KC will accept, BUT they do recommend anybody who has only been in the breed for a short period of time, to consult with another experienced (in the breed) breeder for their opinion.

Half brother to half sister will help fix type but you must do your research before going ahead.   In my opinion.

Usually if a breeder does this, perhaps to find out if there IS anything lurking, they go to an outcross the next time (with a daughter from that mating).

There is absolutely no way I would breed a COI that high.

If breeders repeatedly breed above average COIs, you are just breeding toward the extinction of your breed.  Is that what you want?!  A good breeder should be a custodian of a breed, not breed towards its extinction!!  Equally, as a puppy buyer, I will only buy puppies whose COIs are at or below breed average.  This is as important to me as health testing and all the other things I look for in a puppy.

http://www.instituteofcaninebiology.org/blog/coi-faqs-understanding-the-coefficient-of-inbreeding

I suppose it depends what your breed is like numerically. Our breed average is 10.9% and I've just line bred a litter with a COI of 15.7%. The dam is from my outcross litter with a COI of 6.6% (a 3000 mile round trip with her to the sire because the dogs I would choose in the UK are too closely related) and the sire from a litter with a COI of 12.4%. Those figures are acceptable to me and are lower than a lot of litters in our breed.

> There is absolutely no way I would breed a COI that high

Do we know what the COI is? I don't think you can make that statement without knowing. A half brother/sister mating with no other duplicates in the pedigree is 12.5% over 10 generations, that would be considered acceptable in most (if not all) breeds.

> There is absolutely no way I would breed a COI that high.<br />

Which is why I pointed out that ..... "Half brother to half sister will help fix type but you must do your research before going ahead."   And again, 'doing research' means taking advantage of the knowledge and experience of those who KNOW, together with knowing that if anybody does a close(r) mating, they need to go out again, probably the next time, with a daughter of such a mating.    And actually outcrossing can be very successful, or a disaster because when two lines that have never been put together before, the unknown can appear.

All the joy and heartbreak, and challenge of breeding.

But there's just no reason (at least given so far) for it, chaumsong.  There would have to be 2 incredible and outstanding dogs, both fully health-tested and highly qualified either in the ring or in a performance sport.  I'm not just talking limited success, I'm talking WOW factor.

I detest when people use their own stud dog simply because they own the dog - rather than go to the effort of using the best dog for that bitch, whoever owns him.  Far more effort involved in using an outside stud.

mamabas, I wasn't contradicting what you said, just responding to the original post.

> I detest when people use their own stud dog simply because they own the dog - rather than go to the effort of using the best dog for that bitch, whoever owns him.

Actually in linebreeding it is the opposite that usually is a problem, when many people want to use the best dog, and line breed to that best dog, which is when COI becomes to creep up.

What, so using an external stud dog means the COI goes up?  Nope, sorry.  You've got a perfect example here of someone wanting to use their own dog and the COI being extremely likely to be above average as a result so I'm not really seeing that correlation. Using an external stud means you can check COIs before breeding. This is possible because you have a choice from the whole gene pool and not just the one dog you happen to own.

> when many people want to use the best dog, and line breed to that best dog, which is when COI becomes to creep up.

..... and the gene pool is reduced - to say nothing of any problems that highly successful stud dog has (and they all have some, however successful in the ring!) being doubled up on over immediate future generations.   It happened with a very successful dog in my main breed some years back.   It's up to the owners of such dogs not to let them be over-used, in my opinion.

Half sibling matings give at least a COI of 12.5%.

My youngest champion bitch is from such a mating,  the mother of both parents at the time of mating had 3 healthy litters and grand children on the ground,  and was an exceptional quality bitch,  from my 4th generation of breeding.  She was a fit healthy veteran.  She actually was fit and active to 15 1/2.

Both the males producing the two half siblings that were mated were imports from different continents.

Apart from a small choice of available sires in my breed the aim was to stabilise on the known qualities of my bitch.

It is not a mating I would advise without a lot of thought,  and knowing where you can usefully outcross in next generation.

Equally of course an outside dog could yield just as high a COI,  ownership is irrelevant.

As MamaBas said "Half brother to half sister will help fix type but you must do your research before going ahead." What you have to remember is that if there is anything iffy in the lines, that too will be locked in. Do you have access to someone whom has been in the breed a very long time and knows the lines thoroughly? If you do, then seek out their help and advice. There maybe something back in the lines that has been lost-in-the-mists-of-time (so to speak)and that you really do not want to be doubling up on.

I think you have to look further ahead.  COIs across all breeds are rising.  COIs across all species (not just dogs) should ideally be kept at 5% or lower to keep the risk of inheriting recessive genes low.  COIs at 10% or higher are going to start to show some effects from higher COIs.  This may be smaller litter sizes (as fertility is affected), higher incidence of disease, weakened immune system/immunological issues.  And so on. 

But more importantly, every breed only has a limited amount of genetic material.  At the time the stud books closed, all the dogs included in a breed represented the maximum amount of genetic material available.  Over time, as breeders select for specific features or abilities, some genetic material is lost.  As popular sires get used more and more, whilst other dogs are never used, so some genetic material is concentrated in the breed as a whole, whilst other material is lost forever.  When it is lost forever, it cannot be regained.  This is happening all the time.  Which is why most breeds have an average COI which is way over 10%. 

If this is perpetuated, breeds of dog are either going to start encountering severe physical problems which can't be gotten out of because they affect all individuals in the breed - or all are Carriers.  Such as the situation with Dobermans at the moment.  Eventually, breeds will become so unhealthy as either to die out altogether or the stud books will have to be reopened and other blood from other breeds admitted - more and more.  To delay this needing to happen and to ensure dogs are physically healthy and can live happy lives, it is incumbent on good breeders to do all they can to lower COIs and to keep them low.  This is more important than what your dog looks like, or how many CCs it can rack up, or whether it wins at performance events - it is literally about the survival of the breed in the long-term.  The survival of a breed, the health of dogs, is more important than how many CCs and titles you (individually) with your (individual) dog can rack up.  It's about doing the greater good for the breed as a whole and selflessly serving what you purport to love.

And if you do have amazing dogs and decide to inbreed slightly, then you have to compensate for that somehow, in future breedings and generations by doing all you can to then lower that COI and use rare genetic material.

Breeders need to be prioritising preserving the gene pool in as wide a way as possible:  Identifying rare genetic material which will be lost if not perpetuated and using that.

> But there's just no reason (at least given so far) for it, chaumsong.  There would have to be 2 incredible and outstanding dogs, both fully health-tested and highly qualified either in the ring or in a performance sport.  I'm not just talking limited success, I'm talking WOW factor.

Oh I absolutely agree with your entire post, I was simply commenting that the COI is not that high, probably within normal range of most breeds and low for some.

I cwrtainly agree that breeders need to look to the effect on the gene pool when making breeding decisions,  and look beyond the current mating to what the offspring,  and future generations will provide,  and can be used with.

It would be good if the KC tools would allow for further generation plans in their hypothetical mating tool.

MYKC is very useful for breeders to check how many litters and to what bloodlines a given dog has been used.

I certainly think that as a guide we should be looking at the advice in other countries and avoid using dogs that have produced more than 10% of the last 5 years registration numbers in their lifetime.  In my breed that could be no more than 4 or 5 litters in their life

I Would not want to see hard and fast limits,  as of course numbers are not the whole picture,  as a lot depends on how many offspring are in turn bred from.