Genetic diversity, inbreeding and breeding practices in dogs: results from pedigree analyses.

Pedigree analysis constitutes a classical approach for the study of the evolution of genetic diversity, genetic structure, history and breeding practices within a given breed. As a consequence of selection pressure, management in closed populations and historical bottlenecks, many dog breeds have experienced considerable inbreeding and show (on the basis of a pedigree approach) comparable diversity loss compared to other domestic species. This evolution is linked to breeding practices such as the overuse of popular sires or mating between related animals. The popular sire phenomenon is the most problematic breeding practice, since it has also led to the dissemination of a large number of inherited defects. The practice should be limited by taking measures such as restricting the number of litters (or offspring) per breeding animal.