Double-chambered right ventricle, ventricular septal defect, patent ductus arteriosus in a dog

A 4-month-old female mongrel puppy was presented with an anophthalmos. On physical examination, systolic murmur was heard at the 4th left intercostal space near the sternum. However the dog appeared healthy without cyanosis and had no history of exercise intolerance. The phonocardiogram revealed a pansystolic murmur and a continuous murmur on the mitral area. A systolic ejection murmur was also recorded on the pulmonic area. The electrocardiogram indicated bi-ventricular hypertrophy. Left ventricular enlargement was seen on chest radiographs. Ventricular septal defect (VSD) and patent ductus arteriosus (PDA) were diagnosed from these findings. PDA closure was performed at 2 years of age. After 2 months from the operation, the dog died during an attempted repair of the VSD. At necropsy, it was found that the double-chambered right ventricle (DCRV) was formed by an anomalous septal band. The VSD was localized on the proximal conus and was 8 mm in diameter. (author)