Today’s case is a 5 month old female Shih Tzu with a heart murmur. What is your top differential diagnosis?
The cardiac silhouette is moderately enlarged, with a bulge in the region of the main pulmonary artery on the dorsoventral projection. There is a vascular pattern with diffusely enlarged pulmonary vasculature throughout the pulmonary parenchyma. No other abnormalities are noted in the pleural space, mediastinum, or musculoskeletal structures. The portion of the abdomen included is normal.
Congenital cardiac anomaly – patent ductus arteriosus.
The vascular pattern and cardiac enlargement indicate a left to right shunt, and the bulge in the main pulmonary artery is characteristic of a PDA. Because of the dog’s small size (1.6 kg), coiling was not an option. The PDA was surgically ligated successfully.