Abstract
There is limited information describing species related pharmacogenetic differences in animals. Despite the lack of genetic information in veterinary medicine, breed specific responses to endogenous and exogenous substances have been reported across many species. This finding underscores the importance of obtaining insight into the genotypic and phenotypic variation present across breeds. This article provides a summary of the literature pertaining to canine breed differences in physiology, drug response, drug pharmacokinetics, and metabolic idiosyncrasies. The existing knowledge of pedigrees and the known phenotypes and genotypes of dogs provides important information for determining mode of inheritance, penetration, and other major characteristics of heritable traits. Understanding these breed differences will improve canine population predictions (for canine drug products) and may be of value when extrapolating toxicology data from dogs to humans.