Patent Ductus Arteriosus (PDA) is one of the most common congenital heait defects of dogs. Clinical signs commonly observed with this condition can range from asymptomatic to severe congestive heart failure (pulmonary edema). Physical exam findings are commonly correlated with how much blood flows through the PDA and into pulmonary circulation.A high-grade, continuous ("machinery") heart murmur with bounding femoral pulses in a young dog (usually <l year) is almost pathognomonic for this condition. Physical exam findings and the signalment alone can be highly suggestive of this disease, but an echocardiogram is often used to visualize the PDA, assess heart structure and function, and rule out other congenital heait defects also. Surgical ligation or trans-arterial catheter-guided occlusion has been shown to cure this disease and carries an excellent long-term prognosis in cases that have not progressed to congestive heart failure or have shunt reversal (right-to-left shunting).