Confirming Renal Failure In Cats With Lab Tests

Feline renal failure is characterized by a cat kidney or kidneys' inability to function properly. A cat in renal failure has kidneys that no longer work to rid the body of waste. As the kidneys loose their ability to function an imbalance in the cat's body chemistry (due to the inability to properly alleviate the body of waste) will occur, slowly poisoning the animal. Renal failure in cats is very common, and it is suspected that a the kidneys are sensitive to high protien levels and therefore protient levels should be monitored carefully. Lab tests are used to confirm cases of chronic renal failure (CRF). If you are concerened about your cat lab tests to screen for CRF should be requested at his annual check up.

Blood Tests

BUN & Creatinine - A blood sample to measure the BUN and creatinine levels is key in diagnosing CRF.

BUN is excreted through the kidneys as a waste product, and reflects the impact the cat's diet has had on its system. A higher level of BUN may be indicative of dehydration, which is a common symptom of CRF, and other diseases like IBD.

Creatinine is another waste product excreted through the kidneys and an indicator of how the kidneys are functioning overall. An increase in creatinine and BUN levels indicates that kidney function has failed by approximately 70%, meaning the cat is in Chronic Renal Failure.

A protein creatinine ratio can also be performed as part of a urinalysis.

It is suspected that hypertension (high blood pressure), hypokalemia (potassium deficiency), and feline dental disease may be linked to the development of CRF: Your cat should be tested for these conditions as part of his annual check up.


Urinalysis is preformed to test the urine's pH level as well as other elements within the urine. Since the most pertinent diagnostic information regarding CRF is gathered from blood tests, it is not necessary to have a urinalysis performed with the same frequency as blood tests.

Specific Gravity - Specific Gravity is a measure of how well the kidneys are working to filter urine, measuring their overall ability to function as the organ is meant to.

CRF disables the kidneys' ability to concentrate urine properly, and therefore an abnormally low specific gravity is a sign of kidney failure.

Urine Culture & Sensitivity Screening - Kidney failure can be caused by a bacterial infection, making it important to have a urine culture and sensitivity test performed to check for the presence of a bacterial infection. This procedure will determine if an infection is present, and if so, what the exact type of infection it is. Once diagnosed, antibiotics may be administered to help fight the infection.

E.D.R. HealthScreening Feline Urine Test - Screening for glomerular disease, detected by the presence of microalbuminuria (small amounts of albumin) in the urine, can help make an early diagnosis of a variety of different diseases affecting the feline kidneys, including CRF. Glomerular disease occurs when proteins, and sometimes red blood cells, leak into the urine indicating damage to glomeruli which can then interfere with the kidney's ability to clear waste from the body.

While there is no cure for feline renal failure, early detection may help to increase longevity and quality of life. If your cat is over the age of seven, make sure that a full blood panel is performed at his annual check up to screen for CRF and other age related diseases.

Biopsies, ultrasounds, blood pressure, and GRF testing are also available to aid in diagnosing CRF.

If your cat tests positive for CRF, ask you veterinarian about treatment options for your cat. Renal disease specific foods (you may be able to acquire some of these foods from your veterinarian as a preventative measure), and medications may be prescribed, along with subcutaneous fluids to keep your cat well hydrated and assist the kidneys in function. Remember that the use of "sub-q" fluids may affect potassium levels, so be sure to follow dosing directions as prescribed by your veterinarian.