Pulmonary arteriovenous malformation and a concurrent patent ductus arteriosus in a Doberman

A 7-week-old male Doberman presented with tachypnea, dyspnea and a VI/VI, left cranial, continuous heart murmur. Thoracic radiographs revealed severe left-sided cardiomegaly, presence of a rounded soft tissue opacity in the caudodorsal aspect of the thoracic cavity and signs of left-sided congestive heart failure. Clinical signs of heart failure were medically controlled. Echocardiography and computed tomography demonstrated a left-to-right shunting patent ductus arteriosus (PDA) in combination with a right-to-left shunting pulmonary arteriovenous malformation (PAVM) between the right main pulmonary artery and the right caudal pulmonary vein. Arterial blood gasses revealed mild hypoxemia. Transcatheter occlusion of the PDA using an Amplatz Canine Duct Occluder was performed. Four months post-operatively, echocardiography showed normal cardiac size and function with complete PDA closure. Thoracic radiographs revealed absence of the rounded opacity and resolution of cardiomegaly and vascular congestion. The PAVM was no longer visualized on repeated computed tomography and the arterial blood gasses were within normal limits. A PAVM connecting a pulmonary artery to a pulmonary vein has only rarely been reported in dogs. This report describes the presence of a congenital PAVM in combination with a PDA in a dog, which has not been previously reported in veterinary medicine.