The field of veterinary medicine refers to the branch of medical science that deals with the prevention, diagnosis and treatment of diseases in animals. It involves the study of animal anatomy and physiology, as well as pathology, pharmacology, surgery, dentistry, nutrition, reproduction, and herd health management. Veterinarians work with a wide variety of species, from household pets to large animals such as horses or cows, treating them for illnesses, injuries, or other medical conditions. The field also encompasses the study of zoonotic diseases, which are those that can be transmitted between animals and humans.