Thursday, January 24, 2008

The Dangers of Inbreeding

Patrick and I tend to go on about how the closed- studbook model of breeding and breeds, a relict of the 19th century's imperfect understanding of genetics, is deleterious and dysfunctional, but I haven't said much on it here. Reader Mike spies and I recently had an interesting discussion on this matter,and he gave me permission to post. Mike first:

"Dogs bred from FDSB registered animals have provided excellent, successful
hunting and trial dogs for about 100 years.
On the subject of inbreeding - this is often confused with line breeding.
Combined with rigorous culling and intelligent planning, line breeding
produces fine, sound animals that are largely free of genetic problems.
Further, the overall quality of a line breed litter is more likely to be more
predictable and consistent (pup to pup) than a litter produced by a pure out
cross - the genes combine in more predictable ways. Line breeders do out cross
- to other line bred, but less related dogs to inject proven new blood into
their breeding programs."


"I know these things and agree to a point. But you CANNOT breed forever in a limited pool without deleterious genes being expressed-- a real outcross is needed once in a while (not necessarily constantly). If you outcross type to type is better of course.

"(I know this a bit from 50 years of breeding pigeons, where the generations go faster and mistakes are less heartbreaking. But also, what -- ancient-- academic training I have is in evolutionary, genetic, and population biology.)

"And: the situation is also different with the saluki- tazi (taigan aboriginal Afghan) meta- population, which until recently stretched from north Africa to Mongolia and consisted entirely of working dogs. Now, show breeders have ruined (most) western salukis and (almost all) western "Afghans", with their silly hair. Worse, the rise of nationalism in Central Asia has made several nations there decide their local race is a "breed" and close studbooks. My extremely functional Almaty pair are too closely bred for my liking , which is why I am welcoming to the Ukrainian southeast tazis and the similar Russian ones, even though they are not quite as perfect. I am taking a long view.

"But so much-- I know this is a digression-- is being lost. Ten years ago you could still get tall black intergrades of the tazi and taigan populations in Kyrgizstan. I'd kill to have such a dog, but the state is discouraging their breeding, never mind export, because they are not 'pure". AAARGH!

"But the principles of outbreeding expressed in the essay will work for -- call them tazis--because there is still a considerable and remarkably physically and mentally consistent working population-- for a little while anyway-- and they are from such a large area one can find good ones thousands of miles apart. I may outcross eventually to both Arabian and Kurdish dogs ( I know a female from Iran who is the same Turkmeni type as my Ataika!) I should add these are all hunting dogs owned by friends in California, Virginia, and here in NM.

"I should add that-- with the exception of a pretty- well failed one- time attempt in basenjis-- the saluki, to the horror of show people, is the only breed that the AKC lets bring in "Country Of Origin" dogs. I know several HUNTING saluki people salivating for my dogs' genes!

Mike again:

"The breeding programs that produce many of the finest examples of sporting
breeds are carried out by informed small scale breeders who test their dogs in
competition, constantly winnowing parents for the traits they desire. They
breed the best examples that they can find. Many could be labeled 'back yard
breeders' - a term that implies an unscientific, uninformed, and haphazard
approach to breeding. - a not-quite-a-lie for the media and the uninformed.
The finest dogs that I have owned have come from such breedings. The bigger
the breeding operation, the more difficult it is to produce a quality puppy."

And me:

"Agree completely. My bird hunting pal Omar here in town has had three excellent pointers from two local breeders as good as any I have ever seen. And I am a backyard breeder myself, as are my friends mentioned above. I think we are the true conservators."

Soon: another "meta- population": flock guardians from Wyoming, Mongolia, and more...


dr. hypercube said...

"Ten years ago you could still get tall black intergrades of the tazi and taigan populations in Kyrgizstan. I'd kill to have such a dog..."

Me too - is it out of the question at this point?

Steve Bodio said...

If I had money...

I'd look in remote mountainous parts of BOTH K- Stans, using my tribal- connected friends, who boast of relatives' big black dogs, rather than my scientist friends who are in thrall to the western breed paradigm. Archaeologist Renato Sala, based in Almaty, has also seen such dogs.

I'd favor Kazakhs in the Tian Shan because I have only one contact in Kyrgizstan and he is very committed to strict breed lines-- I doubt he would let a "mutt" out.

Mike Spies said...


I have been thinking about our exchange on this subject off and on for a week or so. I think that the issue, one you referred to obliquely in your post, is the size and homogeneity of the breeding population - the gene pool.

As you know, I keep field bred English setters. The gene pool of performance proven animals is quite large, so the opportunity to go outside a line and bring in other dogs similar in type, but with new genetics is large. In the main the people breeding have a fairly consistent vision. To introduce totally new blood introduces significant variability and is really not necessary.

In your case, the breeding pool of available PERFORMANCE PROVEN dogs is probably quite small. The number of people breeding the type is probably small as well. So you are, it seems to me, attempting to resuscitate a TYPE of dog using the best genetics you can reasonably find. In your situation, I would do the same thing.

I would not look to 'Breed Clubs' - their dogs are not the type that can do what you need. Breed standards and purity do not apply. Performance does.

dr. hypercube said...

"On the subject of inbreeding - this is often confused with line breeding."

Line breeding is a particular type of inbreeding.

Mike Spies said...

Line breeding means:

"The mating of related animals less closely related than inbreeding."

Line breeders usually breed out every couple of generations to similar, but unrelated, line-bred dogs. This greatly diminishes the possibility of the 'deleterious effects' of inbreeding.

Actually there is no agreement among breeders about where the line between inbreeding and line breeding is, exactly. There have been a number of very healthy and successful field trial dogs with COIs as high as 16.5. The average competitive setter is probably closer to 3.0 to 6.5 COI. I have one that has a 10 generation COI of 12.0 and is a very fine animal.

Line breeders do not breed brother to sister as an inbreeder might. They may breed a sire to a littermate's offspring to better fix characteristics that they value. The effects of in-breeding and at what level of COI they are manifested in dogs is not well explored with performance dogs that are bred and culled by breeders.

Carolina wild dogs are a small population that has apparently bred in the wild for many hundreds of years. As long as Darwinian principles are at work there appear to be no deleterious effects of inbreeding in this small population.