# Inbreeding Coefficient Questions



## poodlesplease (Sep 6, 2011)

As a non-breeder, I have been a little confused about this value and what is acceptable or a good guideline vs, wow this is way too high. I have a couple of breeders that I am happy with that have upcoming litters, but I just wanted some of the experts to way in on this number.


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## Countryboy (May 16, 2011)

The experts will probably jump in to this thread soon. But, in the meantime, the Coefficient of Inbreeding has been discussed in many threads on this forum. U may want to do a search under 'COI' for a little background. It brings up a lot of information.


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## poodlesplease (Sep 6, 2011)

I did some searching before I posted, however I did not find anything, when I broadened to the entire forum and searched inbreeding (COI is a difficult search term because of length), there are a lot of threads that I found helpful in the Poodle talk boards.

Thanks!


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## ArreauStandardPoodle (Sep 1, 2009)

I agree with Countryboy. This has been discussed many times. As a breeder, we shoot for COI's on our puppies of less than 7%. Have you read the Canine Diversity Project's info on COI? It is very helpful and informative!!


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## Countryboy (May 16, 2011)

If u search 'Coefficient of Inbreeding' it wouldn't surprise me that there would be very little hits. Probably 'coz nobody here would bother to type in the whole phrase. 

We mostly use the acronym, COI. Search that, and u'll get 195 hits.


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## zyrcona (Jan 9, 2011)

The COI measures the number of ancestors repeated in a pedigree, and thus how inbred a dog is. Generally, the lower the COI, the better, as inbreeding results in inbreeding depression. However, for any breed, if you go back far enough there are going to be ancestors repeated, because the number of ancestors increases exponentially with each generation, and you'll reach a point where there were simply not enough dogs in existence at the time.

Also, at one point in history, inbreeding was thought to be a good thing, and it's hard to find a dog without a closely inbred pedigree somewhere in its background. I found a bitch in a pedigree once who was bred to her dad, who was also her half-brother and her uncle or something stupid like that.

COI can give you a ballpark figure, but you have to look at the pedigree and where the inbreeding occurs to get more information. If the inbreeding occurred many generations back, then its effect is diluted in the dog as compared to an inbreeding in a recent generation. Also, crossing breeding together two extremely inbred dogs from very different lines with little inbreeding _between _them will result in very heterozygous puppies who will have little inbreeding depression despite a higher COI than would normally be acceptable.

Some general inbreeding numbers, assuming no prior inbreeding:

6.25% cousin breeding. The closest normally allowed in humans. Generally considered a safe COI.
25% parent to child or siblings. Considered too high, and unregisterable with the Kennel Club.
12.5% half sibling cross, or uncle/aunt to niece/nephew, grandparent to grandchild. I would consider this too close, although other people's opinions may differ.


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## NOLA Standards (Apr 11, 2010)

It seems that COI is being used somewhat as a sales tool/pitch for puppy selling. "All our pups are bred to a low COI". Back yard breeding mating Yard Dog 1 to Joe's Intact Male 2 would - more likely than not - present with a low COI.

Low COI does not = a quality breeding.

There's quite a bit more to be considered than a low COI, and as Zyrcona noted, much more to a pedigree than might immediately meet the eye. So consider it a tool, but certainly not the "be all end all" and don't assume a low COI means the breeder knows what they are doing. 

As I mentioned at the start of this thread "low COI" along with "from Champion lines" and "rare/desired color" (and there are others but I'm starting to gag a bit) are all being touted by BYBs these days to misdirect and sell, sell, sell!

Tabatha
NOLA Standards


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## ArreauStandardPoodle (Sep 1, 2009)

It is not just BYB's touting the good in pups with low COI's. I have seen quite a number of quality show breeders who have made low COI's a priority. To me, it is obvious the importance of striving to lower the numbers. I am now able to search the dogs I grew up with when COI was not even a term heard in breeding and in-breeding seemed to be the norm. The dogs with lower COI's lived to be about 14 years old. The dogs with a much higher percentage lived to be about nine. It is indeed just another tool we can use, but one which myself and anyone I co-own with feel is extremely important. Most threads that have been started regarding COI's have usually been full of disagreement.


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## Rayah-QualitySPs (Aug 31, 2010)

When comparing coefficient of inbreeding, COI, make sure you are using the same amount of generations in the pedigree.

A 10 generation pedigree should be the norm not just 4 or 5 generation. 

Scientifcally inbreeding and linebreeding are the same thing and interchangeable terms; some breeders like to differentiate between the terms.

This number is just a tool that allows breeders to pick whom to bred to whom. Overall in the big picture the lower the number the better but realistically the inbreeding depression is based on large numbers.

Breeders in Canada and the United States can and do breed father to daughter or son to mother. There are no registry restrictions on these breedings.

One of the best websites to learn more about inbreeding depression and coefficient of inbreeding is the Canine Diversity Project at Canine Diversity Homepage 

Thanks for educating your self before buying a puppy.


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