Veterinary medicine, also called veterinary science, medical specialty concerned with the prevention, control, diagnosis, and treatment of diseases affecting the health of domestic and wild animals and with the prevention of transmission of animal diseases to people. Veterinarians ensure a safe food supply for people by monitoring and maintaining the health of food-producing animals.

Veterinary medicine has made many important contributions to animal and human health. Included are dramatic reductions in animal sources of human exposure to tuberculosis and brucellosis. Safe and effective vaccines have been developed for prevention of many companion (pet) animal diseases—e.g., canine distemper and feline distemper (panleukopenia). The vaccine developed for control of Marek’s disease in chickens was the first anticancer vaccine. Veterinarians developed surgical techniques, such as hip-joint replacement and organ transplants, that were later applied successfully to people.

A major challenge to veterinary medicine is adequately attending to the diversity of animal species. Veterinarians address the health needs of domestic animals, including cats, dogs, chickens, horses, cows, sheep, pigs, and goats; wildlife; zoo animals; pet birds; and ornamental fish. The sizes of animals that are treated vary from newborn hamsters to adult elephants, as do their economic values, which range from the undefinable value of pet animal companionship to the high monetary value of a winning racehorse. Medicating this variety of tame and wild animals requires special knowledge and skills.