A phenomenon in canine competition circles known as popular sire syndrome can produce strong, competitive and intelligent puppies that go on to become, and produce, champions. The occurrence can also produce puppies that fill the breeding pool with genetic maladies.
When a male dog wins a prestigious championship, he obviously has what it takes to win at the highest levels. The effect is that his value as a stud dog skyrockets as breeders with females hope to produce puppies that can replicate their father’s accomplishments.
Often that trendy stud dog is bred with many female dogs throughout the country. When this happens, you can see that male dog show up in pedigrees from previously unrelated lines. In a large breeding pool, say with Labradors, the effects aren’t as profound as in a smaller population, but they’re still present and can cause issues for future generations regardless of population size. If that popular stud dog has any genetic disorders in his DNA, his puppies will likely harbor those mutations – at best becoming carriers and at worst being affected with the related disorder – and can continue to contaminate the breeding pool.
Even in a large breeding population, the bottleneck ...