Kidney Disease in Cats

Learn the signs of kidney failure in cats.

Kidney disease (also called renal disease or renal insufficiency) is an extremely common diagnosis made in cats. Older cats, especially, develop kidney disease, but it can be found at any age.

Kidney disease is sometimes called kidney failure, though there are degrees that range from mild to severe.

What Do the Kidneys Do?

The kidneys are a pair of organs that are part of the urinary system. They are made up of nephrons, which process chemicals to separate those the body needs to keep from those that need to be discarded. The ones to be discarded are mixed with water and sent from the kidneys to the bladder, to be removed from the body as urine.

It's also the kidneys' job to keep hydration levels normal in the body. So, if a cat is dehydrated, the kidneys conserve water by concentrating the urine. That means that the waste materials must be mixed with less water before being removed from the body.

What Is Kidney Disease?

Kidney disease occurs when the kidneys lose their ability to properly separate needed from unneeded chemicals in the body efficiently. It may happen because of decrease blood flow to the kidneys or because too many nephrons are destroyed, leaving too few to do the job well.

When this occurs, toxins begin to build up in the cat's blood stream, and these interfere with various other bodily functions and make the cat feel sick.

Signs of Kidney Disease in Cats

Often, the first thing that happens when the kidneys begin to fail is that the cat drinks excessive amounts of water. This happens because the kidneys have lost their ability to concentrate the urine efficiently, so they keep "asking" for more water to do their job. Increased water consumption and urination, including inappropriate urination, are extremely important signs of early kidney disease in cats to be aware of and have checked out by the veterinarian.

Other signs of feline kidney (renal) disease include:

Causes of Feline Kidney Disease

Kidneys can fail acutely, or suddenly, or chronically over a long period of time. Acute kidney failure is usually caused by a toxin, infection, or trauma. Chronic kidney failure may be the result of age or other disease processes that affect the kidneys.

Diagnosis of Feline Renal Disease

Diagnosis of kidney disease in cats requires a complete physical examination by a veterinarian. The doctor will also run blood tests and a urinalysis. Below are some of the common tests and the results that may be seen with feline kidney disease:

Staging of Kidney Disease in Cats

Cats' kidney disease can be staged based on their blood creatinine levels. Levels between 1.6 and 2.8 mg/dL indicate Stage II, or mild failure. Levels between 2.8 and 5 mg/dL indicate Stage III or moderate failure, and levels over 5 mg/dL put the cat in Stage IV or severe failure.

There is also a fairly new test called SDMA, offered by IDEXX labs, which can indicate the presence of kidney disease even before creatinine levels are high. A high SDMA level can prompt further diagnostics and increased monitoring of a cat, so kidney failure can be slowed down as much as possible. This test is often done yearly, as a routine to catch a problem early.

Treatment of Feline Renal Disease

Treatment of your cat's kidney disease will depend on her individual circumstances and test results. Here are some things your veterinarian may wish to do with your cat:

Prognosis for Renal Failure in Cats

Kidney disease in cats can't be reversed, but it can often be managed for long periods of time. The prognosis varies widely based on the cause of the condition, how aggressively treatment is pursued, and how well the cat handles the treatment.

You May Also Like These Articles:

Polycystic Kidney Disease (PKD) in Cats

Easter Lilies: A Holiday Hazard for Cats

Feline Hypertension

Hyperthyroidism in Cats

Should Cats Get Tap or Filtered Water?

Dehydration in Cats: How Can You Tell If a Cat Is Dehydrated?

Top Ten Emergencies in Cats

Foods Toxic to Cats - Slideshow

Disclaimer: This website is not intended to replace professional consultation, diagnosis, or treatment by a licensed veterinarian. If you require any veterinary related advice, contact your veterinarian promptly. Information at is exclusively of a general reference nature. Do not disregard veterinary advice or delay treatment as a result of accessing information at this site. Just Answer is an external service not affiliated with