Acquired Gerbode defect and third-degree atrioventricular block secondary to vehicular trauma in a dog

To describe a case of traumatically acquired left ventricular to right atrial communication (Gerbode defect), atrial septal defect (ASD), and third-degree atrioventricular block (AVB) necessitating permanent pacemaker placement in a dog.

A 1.5-year-old neutered male Newfoundland dog was struck by a car and was referred for further evaluation and treatment of hemoabdomen. Persistent third-degree AVB, a right-sided cardiac murmur and right-sided congestive heart failure (CHF) were identified, and echocardiographic examination revealed a type-A Gerbode defect and ASD. Pimobendan, furosemide, and enalapril therapies were initiated for treatment of CHF. Persistent AVB eventually necessitated permanent pacemaker implantation. Initial attempts at minimally invasive occlusion of the Gerbode defect were unsuccessful; however the dog continues to do well clinically on chronic cardiac medications.

To our knowledge, an acquired Gerbode defect secondary to trauma with associated ASD, CHF, and third-degree AVB necessitating permanent pacemaker therapy have not yet been reported in the veterinary literature. The extended survival and follow-up available on this patient postpacemaker implantation also documents that longer term survival is possible with this defect.