Abstract
Two dogs with patent ductus arteriosus and severe pulmonary hypertension were presented to our veterinary teaching hospital. In both dogs, sildenafil was initiated to treat pulmonary hypertension, and surgery was supposed to be scheduled after dose titration. Although no obvious improvement in pulmonary hypertension was observed, no dog had polycythaemia or an increased haematocrit level. The dogs underwent ductal occlusion, and treatment with beraprost sodium was subsequently initiated. Thereafter, severe pulmonary hypertension dramatically improved. No dog showed any clinical sign of right heart failure or adverse drug reaction postoperatively, thereby demonstrating the successful treatment of two dogs with patent ductus arteriosus and severe pulmonary hypertension, using sildenafil and beraprost sodium.