Atrial septal defect in an Airedale terrier

A 2‐year‐old, female spayed Airedale terrier presented for evaluation of a heart murmur noted during an annual wellness examination. Physical examination revealed a grade IV/VI, left basilar systolic heart murmur. The remaining physical examination was unremarkable. Thoracic radiographs and an echocardiogram were performed. Radiographic findings included right‐sided cardiomegaly, enlargement of the pulmonic arch and enlargement of the caudal lobar pulmonary arteries. An approximately 2.8 cm (apicobasilar dimension) ostium primum atrial septal defect was observed on echocardiography. The dog was discharged with conservative therapy of pimobendan (5 mg PO q12h). As of the most recent recheck, 3 years after initial diagnosis, the patient's heart size remained static.