{"id":628691,"date":"2024-06-24T19:26:24","date_gmt":"2024-06-24T23:26:24","guid":{"rendered":"https:\/\/www.singlecare.com\/blog\/?p=628691"},"modified":"2026-07-09T17:46:11","modified_gmt":"2026-07-09T21:46:11","slug":"spironolactone-for-dogs","status":"publish","type":"post","link":"https:\/\/www.singlecare.com\/blog\/spironolactone-for-dogs\/","title":{"rendered":"Spironolactone for dogs: Uses, dosage, and safety"},"content":{"rendered":"

Spironolactone<\/a> (brand name: Aldactone) is a potassium-sparing diuretic<\/a> that increases water and sodium excretion through urine. Veterinarians never use spironolactone on its own but always combine it with other medications. Pet parents can expect to give their dog one dose daily, either as a tablet or a specially prepared liquid. In some cases, spironolactone is a long-term or even lifelong treatment.\u00a0<\/p>\n

RELATED: <\/b>Discount pet meds & resources<\/b><\/a><\/p>\n

What is spironolactone used for in dogs?<\/h2>\n

In dogs, spironolactone<\/a> is useful in treating congestive heart failure<\/a> and other cardiovascular conditions when other drugs are not working well or causing potassium levels to fall too low. Veterinarians also use it for other purposes, including treating fluid buildup in the belly (ascites), treating high blood pressure<\/a>, and reducing fluid buildup when the kidneys are having filtering problems. For all these conditions, veterinarians only use it with other medications.<\/p>\n

Congestive heart failure (CHF)<\/h3>\n

Heart failure is a condition in which the heart cannot pump enough blood to the rest of the body. In dogs, as in humans, there are many causes<\/a> of heart failure, including genetics, valve disease, fluid buildup around the heart, \u201cback-leak\u201d of the blood, high blood pressure, pulmonary hypertension, and heart structure abnormalities. Valve disease is the primary cause of heart failure in dogs, accounting for about 80%<\/a> of cases.<\/p>\n

Veterinarians choose medications based on the cause. Standard treatment of congestive heart failure includes diuretics<\/a> such as furosemide<\/a> to reduce fluid and drugs that dilate blood vessels, such as ACE inhibitors. Also commonly used is <\/a>a drug that increases the strength of heart muscle contractions called pimobendan, and drugs that change the way the heart beats, such as digoxin<\/a>, beta blockers<\/a>, and calcium channel blockers<\/a>.<\/p>\n

Veterinarians use spironolactone if diuretic treatment is not effective or if the diuretics being used deplete too much potassium from the system.\u00a0<\/p>\n

Ascites (abdominal fluid buildup)<\/h3>\n

Veterinarians call fluid buildup in the abdomen \u201cascites.\u201d Ascites is a serious and potentially life-threatening condition caused by blocked liver veins. Blood vessel problems have several possible causes<\/a>, including blood clots, strictures, swelling, compression, scarring, tumors, or other conditions that restrict blood flow through these vessels. These blood vessel problems are often a consequence<\/a> of other conditions like heart failure, liver failure, or heart disease.\u00a0<\/p>\n

For ascites, veterinarians treat the cause. They only use diuretics to reduce fluid buildup in the abdomen. Spironolactone is added to the treatment to reduce fluid buildup and maintain normal potassium levels.\u00a0<\/p>\n

High blood pressure<\/h3>\n

A dog with systemic hypertension has blood pressures in the arteries that are high enough to damage blood vessels and organs over time. High blood pressure is common among people. The CDC<\/a> reports that 49% of adults in the U.S. have high blood pressure. Most cases involve primary hypertension, that is, high blood pressure that isn\u2019t caused by any other medical condition.\u00a0<\/p>\n

It\u2019s not the same for dogs. High blood pressure is relatively uncommon in dogs. Dogs that do have high blood pressure are usually diagnosed with secondary hypertension, meaning high blood pressure that has an identifiable cause<\/a>, such as kidney disease, adrenal gland problems, or other medical conditions.\u00a0<\/p>\n

When a dog has high blood pressure, veterinarians usually treat the cause. To bring blood pressure back to normal, veterinarians use many of the same drugs doctors use in people<\/a>, including ACE inhibitors such as benazepril<\/a>, angiotensin-II receptor blockers<\/a> (ARBs), beta blockers<\/a>, calcium channel blockers<\/a>, and diuretics<\/a>. Spironolactone is not the first drug a veterinarian will use. Instead, it\u2019s added if other drugs aren\u2019t working or there\u2019s a problem with low potassium levels.\u00a0<\/p>\n

RELATED: <\/b>How to manage high blood pressure in dogs<\/b><\/a><\/p>\n

Glomerular disease<\/h3>\n

Glomerular disease is a type of kidney disease. The glomeruli are groups of small tubules in the kidneys. When blood passes through these small tubules, substances the body doesn\u2019t need, such as water and waste, are filtered into the urine. Substances the body does need, like blood cells and proteins, are filtered so they don\u2019t pass out of the body. Glomerular disease occurs when the glomeruli are damaged and cannot perform their functions, leading to fluid buildup in the body.\u00a0<\/p>\n

Glomerular disease in dogs results from medical conditions such as diabetes, infections, drugs, autoimmune disorders, and other diseases. The veterinarian will primarily address these other causes. To reduce swelling and fluid buildup, veterinarians use diuretics to increase water loss. If potassium levels drop, spironolactone is added to diuretic therapy.\u00a0<\/p>\n

Is spironolactone safe for dogs?<\/h2>\n

Veterinarians consider spironolactone safe in dogs as either a backup or adjunct treatment. Because spironolactone prevents the kidneys from eliminating potassium, it is not safe to give to dogs with high potassium levels. Some medical conditions<\/a>, such as diabetes<\/a>, Addison\u2019s disease, and severe kidney disease, can cause high potassium levels, so spironolactone is avoided in dogs with these conditions. Veterinarians use spironolactone cautiously in dogs with liver disease or dysfunction.<\/p>\n

Side effects of spironolactone in dogs<\/h3>\n

The most common side effects of spironolactone in dogs are:<\/p>\n