Gerbode defect associated with blunt trauma in a dog.

A 6 year-old Labrador retriever was presented after being struck by a car. A ventricular arrhythmia, attributed to myocardial trauma, developed 12 h post-trauma. Echocardiography revealed lesions consistent with a subaortic paramembranous ventricular septal defect (VSD) with shunting of blood from the left ventricle to the right atrium (Gerbode defect). A right-to-left shunting atrial septal defect (ASD) was visualised. Pleural and peritoneal effusions developed within 48 h. Fifteen days post-trauma flow across the ASD was left-to-right while left-to-right shunting across the VSD persisted. No cavitary effusions were detected at 15 days post-trauma or subsequently.