A Case of Canine Atrioventricular Canal Malformation

Abstract

The atrioventricular (AV) canal malformation was observed in a 10-year-old male cocker spaniel weighing 12 kg. Auscultation revealed pansystoilic murmur at the apex and fixed splitting of the second heart sound at the pulmonic area. On the electrocardiogram (ECG), complete right bundle branch block (CRBBB) with right ventricular hypertrophy was shown. Chest X-ray demonstrated an enlargement of the right atrium, right ventricle and pulmonary artery.
Autopsy revealed a partial form of AV canal malformation which involved ostium primum atrial septal defect (ASD I), mitral cleft, hypoplasia of the diaphragmatic wall of the left ventricle and septal inserion of the anterior mitral leaflet.