Pulmonary atresia with intact ventricular septum and agenesis of the ductus arteriosus in a pup.

A 7-week-old Wire Fox Terrier was admitted with pulmonary atresia with intact ventricular septum. The right ventricle and tricuspid valve were hypoplastic, and venous return to the right atrium reached the left side through an atrial septal defect. Oxygenation was via hyperplastic bronchial arteries. There was no evidence of the ductus arteriosus. Physical examination, plain and contrast radiography, and electrocardiography were performed. Clinical findings for this combination of defects were similar to those of more common defects (tetralogy of Fallot, patent ductus arteriosus.