Reversed patent ductus arteriosus in a dog.

A 5-year-old cocker spaniel with tachycardia, > 2 s capillary refill time, arrhythmia, split S2 heart sound, right ventricular enlargement, flattened interventricular septum, dilated pulmonary artery, and slight tricuspid valve insufficiency was diagnosed with reversed patent ductus arteriosus (right-to-left vs the more common left-to-right shunt). Two years later, the dog was still stable.