What is the most common congenital cardiac anomaly found in horses?

The most common congenital cardiac anomaly found in horses is a ventricular septal defect (VSD). This condition occurs when there is an abnormal opening in the septum that divides the left and right ventricles of the heart. The presence of this defect leads to the mixing of oxygenated and deoxygenated blood, which can strain the heart and lungs over time.

VSDs are significant because they can result in clinical signs such as exercise intolerance, heart murmurs, and pulmonary congestion, depending on the size of the defect and the resulting hemodynamic changes. Horses with VSD may exhibit a range of symptoms, from mild effects that do not significantly impact their athletic performance to severe conditions requiring medical intervention.

In the context of congenital heart defects in equine medicine, understanding VSDs is crucial for diagnostic and treatment approaches, making it a key topic in veterinary cardiology.