Congestive heart failure due to bilateral atrioventricular valve insufficiency in two dogs.

Congestive heart failure resulted from bilateral atrioventricular insufficiency was diagnosed in two, small breed, intact male aged dogs. In both cases, the clinical signs were mainly associated with right heart failure, while those related to left heart failure were seldom observed. Radiographic and echocardiographic examinations revealed the dilatation of the right heart due to tricuspid valve insufficiency. Mitral regurgitation was also observed without pulmonary hypertension. Both patients responded to medications of diuretics, methyldigoxin and angiotensin converting enzyme inhibitor. As congestive signs deteriorated, they became unresponsive to the treatment. Ultimately, the dogs died 9 and 13 months later from the first admission.