Furosemide and spironolactone are both diuretic medications used to treat edema in dogs. However, they act on different areas of the kidneys. Furosemide is a much stronger diuretic but spironolactone is potassium-sparing, meaning that potassium stays in the body while excess fluid is being excreted. Your veterinarian will decide which diuretic is best suited for your pet and the condition being treated. No vet writer or qualified reviewer has received any compensation from the manufacturer of the medication as part of creating this article. All content contained in this article is sourced from public sources or the manufacturer. Featured Image: iStock.com/PhotoAttractive