This text book on Physiology of Animals is intended to be useful for elementary animal physiology course in colleges of agriculture, zoology, veterinary and animal sciences. In all chapters, the aim has been to present a clear and concise account of the functioning of various systems of domestic animals. Where appropriate, examples from human and non domestic animals such as rat and rabbit have been cited. Physiology has now grown into a vast discipline.The book covers and explains the following deeply: o Nature and Scope of Physiology o Body Fluids: Water, Electrolyte and Acid Base Balance o Respiration o Blood o Circulatory System o Structure Functions of the Kidney o Rumen Function o Digestion Metabolism o Vitamins and Minerals o Endocrine Glands and Their Secretions o Reproduction in the Male o Female Reproduction o Lactation o Nervous System o Bone, Skin and Special Senses o Physiology of Temperature Regulation