Book excerpt: This book provides essential information on methodologies for recording electrocardiograms in various animal species, including dogs, cats, cattle, buffaloes, sheep, goats, mithun, chelonians, snakes, avians, equines, rabbits, and the Indian gray mongoose. It also reviews the electrocardiographic physiology, generation of electrocardiograms, and normal criteria for various animal species; electrocardiograms in health and disease; and the interpretation of abnormal electrocardiograms, cardiomyopathy and arrhythmias, with corresponding treatment protocols.Further, it presents several approaches to interpreting the electrocardiograms of dogs, cats, ruminants, tortoises, pigeons, and other animals, offering a valuable resource for all veterinary students, scientists, and physicians wanting to make greater use of this valuable non-invasive tool in the diagnosis of heart diseases and general health examinations.