Animal Models in Toxicologic Research: Dog

The development of new agrochemicals, industrial chemicals, and pharmaceutical products requires regulated preclinical safety evaluation trials to determine toxicity and the safe use of these products by society. International guidelines typically recommend studies in at least two species, one rodent and one nonrodent, and the purpose of these studies is to establish target organ toxicity to set acceptable exposure limits for subsequent risk assessment and management of human exposure. The most commonly used nonrodent species is the dog and the beagle breed is almost universally chosen for these purposes. They present an ideal laboratory animal due to their size, temperament, reproductive features, and trainability, and their worldwide use over many years has provided a consistent and well-understood model for human safety assessment with an in-depth knowledge of their reliability in predicting subsequent human organ system toxicity and their background spontaneous diseases. This accumulated knowledge has permitted the use of the dog in safety studies and increasingly in the use of the dog as a model for human cancer, metabolic, and neurodegenerative diseases that will undoubtedly prove invaluable in the coming years. This chapter summarizes the physiology, anatomy, biochemistry, and toxicology of the dog that has made it a critical species in the safety and efficacy of novel drugs, chemicals, and agricultural products for the last 60 plus years.