Furosemide (Lasix, Salix, Disal) is a diuretic used in many species to remove excess fluid from the body. It is used to treat congestive heart failure, some other heart diseases, pulmonary edema (fluid in the lungs), certain kidney diseases, high blood pressure, high potassium levels in the blood (hyperkalemia), ascites (fluid in the abdomen), and certain kinds of tissue edema (swelling). Dosage varies widely depending on condition. Furosemide will cause your pet to urinate more often. Contact your veterinarian if your pet experiences weakness, depression, a change in drinking or urinating, or seizures while being treated with furosemide. People with hypersensitivities (allergies) to sulfa drugs should not handle furosemide, or wear gloves and use extreme caution if they do, since allergic reactions could occur just from contact.