This book based on years of experience in the field of animal physiology represents an attempt to provide students of veterinary medicine with a suitable textbook for their courses in physiology. The book will be useful to students of animal science. This new edition has been thoroughly revised rewritten and updated. Some chapters are completely new and there are many new illustrations. Special attention has been given to developing the book as a teaching tool; to that end and without loss of essential material the text has been somewhat shortened and less emphasis has been placed on research. In addition a more compact format makes the information more accessible to the reader.