This issue of Veterinary Clinics: Equine Practice, Guest Edited by Dr. Colin Schwarzwald and Dr. Katharyn Mitchell, in collaboration with Consulting Editor Dr. Thomas Divers, focuses on Clinical Cardiology. Article topics include: An overview of the equine heart in health and disease; Examination of horses with cardiac disease; Echocardiography; Electrocardiography; Cardiac arrhythmias; Congenital cardiac disease; Acquired valvular disease; Pericardial disease, myocardial disease, and great vessel abnormalities; CV causes of exercise intolerance and poor performance; Assessment of the CV system during prepurchase and insurance examinations; Monitoring of the CV system; Response to exercise and training; and Drugs used to treat cardiac disease.