Disappointed with your diversity results? Don’t be.

So what happens when you get what you think is a “bad” result on your canine diversity test? As this test becomes more widely used, there will be those who test their dogs and are surprised and even disappointed by the results. This phenomenon couldn’t be more true than in our first and most active breed community of Standard Poodle breeders. 

Here’s some background for those of you who are aficionados of other breeds. 

Last century, there were two very popular, successful Standard Poodle kennels, one in Canada on the west coast (Wycliffe) and one in the US on the east coast (Bel Tor.) They both got their foundation dogs from similar sources in Europe and they competed fiercely for dominance in the breed. Both produced beautiful dogs. The Canadian breeder followed the recommendations of scientists at the time and inbred significantly on her foundation stock. The American breeder did some of this as well, though not so severely. The Canadian breeder’s dogs eventually won the most in the ring, and so were bought and bred and exported the most and became dominant in the breed, being bred into every line to improve conformation. The American breeder’s dogs remained popular as well, but eventually became less well known and only dominated pet lines. 
Both kennels went back to 10 dogs born between 1948 and 1953. We in the breed call that the Mid Century Bottleneck or MCB. Fast forward nearly 70 years later and there are no Standard Poodles left on earth without some ancestry attributable to the MCB. Most dogs owe at least 50% of their ancestry to the MCB, and many dogs, especially show lines, owe much more. Some unusual lines only have a small amount of influence  from the MCB, but these tend to be quite obscure. 

(I)f most of the breed goes back to those ancestors, it becomes more and more difficult to avoid the disease genes. This is especially true when the breed specific diseases are caused by multiple genes and factors and there is no way to use traditional DNA diagnostics to find The Disease Gene (as is possible with some diseases) so we can breed away from it. 

So this may be interesting, but why does it even matter? It was 70 years ago! Generations behind us! 

Here’s why it matters. When there is a genetic bottleneck, the genes that become most frequent in a breed are the ones, good AND bad, that existed in the ancestors that make up the bottleneck. This bottleneck can cause a permanent loss of biodiversity that cannot be recovered in a human lifetime, or even several human lifetimes, if ever. Evolution is a very slow process so the genes in our breed 20 generations ago are the only ones in it now, barring sneaky crossbreeds along the way.

In the case of Standard Poodles, the most important ancestors are the 10 dogs from the MCB. If ancestors like these were healthy, had few lurking genetic problems and were themselves quite different from one another, a breed can tolerate a bottleneck reasonably well, especially with careful breeding that doesn’t further narrow the existing gene pool. If those dogs did have lurking genetic disease genes, these diseases eventually become breed specific  diseases, because the disease genes become as common in the breed as all the good genes from those ancestors, and breeders see more and more affected dogs.  Eventually, if most of the breed goes back to those ancestors, which happens as breeders strive for consistency in breed type, it can become more and more difficult to avoid those disease genes. This is especially true when the breed specific diseases are caused by multiple genes and factors and there is no way to use traditional DNA diagnostics to find The Disease Gene (as is possible with some diseases) so we can breed away from it. 

So what can we do? Breeds come with many different genetic landscapes. Some are rare  breeds with lots of diversity, some are popular breeds with little diversity. The careful breed analyses, using the VGL canine diversity test and conducted by Dr Niels Pedersen at UC Davis, have shown that breeds with many ancestors and no bottlenecks like the MCB have fewer breed specific diseases now. That doesn’t make them disease free – or somehow better. It makes them easier to manage. When a breeder runs into a problem, there’s always a line without that problem to breed to in order to avoid the disease. In breeds where the same disease is  very common in all lines, breeding away from the disease is much harder to do.  It can be done if there are enough unusual lines left in the breed with low instances of the disease – but it’s very hard to know which lines don’t have bottleneck influence once a genetic bottleneck is sufficiently infused throughout the breed. The only way to do it without DNA is to look at pedigrees going all the way back to before the bottleneck. This task is highly unwieldy after 10 or 15 generations because it’s thousands of names. For Standard Poodle breeders, this would require them to look at full pedigrees going back to 1948!

Or we can use DNA data. With highly specific, carefully selected, neutral microsatellite markers, we can accurately show genetic relatedness between two dogs and between all dogs in a breed. We can also show how typical for their breed a dog is – indicating more ancestry attributable to a genetic bottleneck – or whether a dog is unusual for their breed – indicating less ancestry attributable to a genetic bottleneck. Lastly we can see how inbred an individual dog is, which can tell us whether they are reasonable candidates for linebreeding or whether any mate they may have should be less related to them so as to avoid any potential negative effects of too much inbreeding.

So back to the original question. What are good or bad results? Breeders want easy answers. They want good/bad, black/white, clear/affected, pass/fail answers. These same professionals who can assess a dog for fronts and rears and angles and movement and color and coat texture and drive and temperament and bloodline health risks – these people who are great at instinctively assessing many variables – they want yes or no answers. 

I’d be lying if I said it worked like that. Or naive. Or inexperienced. Or selling you something. 

But there aren’t easy answers, and don’t buy into anything that says there are. If there were, the dedicated breeders of the last few generations would have solved all the health issues by now.

So the results aren’t good or bad. They are descriptive.  They offer a lot of really important and helpful information that breeders, experts at assessing multiple factors, can use to lower health risks for their puppies while still breeding for traits they love.

If a dog has a low Outlier Index, it means it is more typical for a breed. In Standard Poodles, a low Outlier Index means your dog is more related to those original 10 dogs in the MCB. That’s not good or bad – it’s descriptive. You now know the dog’s ancestry and whether it has higher breed specific health risks. Risks are not the same thing as a diagnosis. There are lots of factors that would mitigate these risks – like knowing the line hasn’t produced any breed specific diseases in a few generations. That would help a breeder put the low OI into context. If, on the other hand, the breeder has been struggling with producing those diseases, they can look for a suitable mate with a higher OI and slowly breed away from that bottleneck, and lower their risks for the breed specific diseases. How does this lower risks? By lowering the frequency of whatever as-yet-unidentified disease genes there are in the line, inherited from the bottleneck. And no matter whether the line is more common or more unusual, breeders should still be breeding to the breed standard as always. 

By managing our historical inbreeding – meaning the impact of bottlenecks on our breed – along with careful selection for robust health,  as well as selection for breed type, we can keep diseases at very low levels even as we preserve the essence of our historic breeds. 

Does this mean unusual dogs are always healthier? Of course not. All lines have health risks and all individuals have some bad genes. So unusual dogs will have different health risks than those of the most common dogs. By managing our historical inbreeding – meaning the impact of bottlenecks on our breed – along with careful selection for robust health,  as well as selection for breed type, we can keep diseases at very low levels even as we preserve the essence of our historic breeds. 
Some breeds don’t have a single specific bottleneck. They may have broad diversity or a lot of small individual lines that are in essence their own miniature bottlenecks. They can assess those factors through the inbreeding estimate, internal relatedness, or IR. Other breeds are actually wholly the result of an old bottleneck and there are few if any unusual dogs left in the breed. In such a case the best option is to keep inbreeding as low as possible in order not to lose any more variation. Those breeds can be healthy or not – depending on the health of their ancestors. 

One fear many breeders have is the idea of bringing disease into their line from unusual lines. We’ve often heard breeders say that the only time they have issues is when they’ve outcrossed. We know now that in many cases a breeding could be considered an outcross on paper but in fact be an inbreeding genetically  – so it is impossible to confirm how often this is actually the result of true outcrossing. However, the best way to avoid bringing in diseases from unusual lines is keeping inbreeding relatively low after the outcross, avoid any significant inbreeding on the outcross, and always to track litters from outcross breedings carefully before breeding them again. Never assume good numbers offer guarantees. They offer lower risk.  Outcrossing is no small commitment, because to do it well requires time for observation. Be sure no new issues crop up. Assess temperaments and conformation. Select your best pups carefully. Be prepared to declare it a disappointing cross. And be equally prepared to declare it a success. 

BetterBred now has over 5250 dog profiles in its database. We have over 2.7 million genetic relationships measured! Most of those dogs have known relatives in the database too, by which we have clearly validated our genetic relatedness calculations.  This data gives breeders power.

There are no good or bad results. There are proven informative results. Breeders can only benefit from more information – they can add that information to what they already know of their dogs, and their lines, for a more complete and helpful picture. 

Want to join us in breed conservation? Register as a free user today and order your test!
Natalie Green Tessier

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