Veterinary medicine is a branch of science that deals with diagnosis, treatment and control of diseases in animals such as livestock, domesticated animals, captive and wild animals, and birds. This is a multi-disciplinary subject that requires knowledge of anatomy, physiology, biochemistry, pathology, animal behaviour, management practices, epidemiological methodologies, statistical procedures and medical ethics and jurisprudence. The core domain of veterinary medicine is to carry out investigation to diagnose the disease and institute proper therapeutics and control measures. The deviation from normal health is termed as disease. The animal is said to be in normal health, when all the physiological functions are normal. The diseases in animals may be hereditary, metabolic, infectious, and contagious or may be due to physical injuries, and chemical and biological causes. The diseases due to biological causes are viral, bacterial, rickettsial, mycotic, protozoal, ectoparasitic and endoparasitic.