This lecture provides a comprehensive examination of the four most prevalent cardiac congenital defects encountered in veterinary medicine: Patent Ductus Arteriosus, Subaortic Stenosis, Pulmonic Stenosis, and Ventricular Septal Defect. Through an in-depth analysis, attendees will gain insights into the prevalence, underlying physiology, diagnostic approaches, and management strategies for each condition. Special emphasis is placed on understanding the alterations in normal blood flow through the heart associated with each defect and the consequent impact on overall cardiac function. By the end of the session, veterinary professionals will be proficient in recognizing, diagnosing, and managing these common congenital cardiac diseases, facilitating optimal patient care and outcomes.