I know we live in a world where Kennel club breeders have lost 70% of their yearly number of registrations since 1976, so what does this say? Could it be a vote for un-pedigreed dogs? Why?
I see two reasons for this: first, the closed registry system and the progressive amount of inbreeding, which is called the Coeffient of Inbreeding or the COI. And second, breeding for more and more extreme conformation.
The closed registry system enrolls the foundation members of a new or recreated breed when they first join the kennel club. Thereafter, in order to be registered with the kennel club, only dogs already registered are to be used for breeding. “The registry is closed and no new members need apply”, is the rule for the vast majority of dog breeds.
If the founding population is over 100 members and grows, genetic diversity will be maintained, unless inbreeding or linebreeding is practiced. If the founding population is less than 100 registered animals, the breed is already doomed to extinction though the inevitable fact that all the dogs end up with too many genes in common. Partly, this is what makes the bred consistent, but a lot of genetic material is lost in every generation because only half of each parents genes are used in the new zygote, the other half is lost. It is inevitable that this genetic attrition continues to reduce the already small gene pool. So What happens? Deeply buried recessives meet each other more often, and genetic diseases develop. Also, genetic diversity is tied to a healthy immune system. When purebred dogs lose genetic material the immune system is weakened.
Breeding for more and more extreme conformation has changed the breeds themselves, especially in the last 50 years. If you visit the blogs I listed under dog genetics, you will find many examples of how the conformation of breeds has become more extreme especially in the dogs that were already the most extreme breeds over this course of the last century.
Weird factoid: Currently, in Los Angeles, it is illegal to breed a dog if it is not AKC registered and actively shown. Yet almost all the AKC breeds are in big genetic trouble.