The genetic diversity of dog breeds has declined significantly, with small founder populations and intensive selection creating hereditary disease burdens that affect millions of dogs.
Dog breed genetic welfare is a structural problem created by closed breed registries and intensive selection for appearance traits. Small effective population sizes create high inbreeding coefficients that increase the expression of recessive deleterious traits. Hereditary conditions including hip dysplasia, epilepsy, and breed-specific cancers cause chronic suffering in millions of dogs. Solutions include mandatory health testing before breeding, open registries that allow outcrossing, coefficient of inbreeding targets, and breed standard reform away from extreme conformations. Consumer demand for health-tested, genetic-diversity-conscious breeders drives cultural change.