Animal disease is a disturbance in an animal's normal state that interrupts or changes its vital processes. Concern for animal diseases can be traced back to the earliest human interactions with animals, and it is mirrored in early religious and magical beliefs. Animal diseases continue to be a source of concern, owing to the financial losses they inflict as well as the possibility of transfer of the causative agents to people. The branch of medicine that deals with the diagnosis, treatment, and prevention of animal diseases is called veterinary medicine. Veterinarians diagnose and treat sick and wounded animals, as well as prevent the spread of animal diseases to humans and advise owners on proper animal care. In veterinary medicine, both the concept of health and the concept of disease are important.