Enalapril is in the class of drugs called ACE inhibitors. It dilates the veins and decreases fluid retention. It is used in the treatment of heart failure, dilated cardiomyopathy, and high blood pressure. It is also sometimes used in the treatment of some types of chronic renal failure. It is often given in combination with other medications such as furosemide (Lasix, Salix). Periodic laboratory tests are recommended during treatment. Contact your veterinarian if your pet experiences weakness or depression while being treated with enalapril.