For the treatment of canine congestive heart failure originating from dilated cardiomyopathy or valvular insufficiency (mitral and/or tricuspid regurgitation). When used in cases of valvular insufficiency in conjunction with frusemide the product has been shown to improve the quality of life and extend life expectancy in treated dogs. When used in a limited number of cases of dilated cardiomyopathy in conjunction with frusemide, enalapril and digoxin, the product has been shown to improve the quality of life and to extend life expectancy in treated dogs.