Kidney Problems

The kidney is an extremely important organ in the body. Its main jobs are to filter the blood and excrete metabolic waste products from the body (urine, urea and creatinine), to eliminate toxins from the body, to regulate water and electrolytes in the body (Na, K, Mg, Cl, HCO3, PO4), to produce erythropoietin (stimulates red blood cells in the bone marrow), and to produce renin (a blood pressure enzyme). If for any reason the kidney is not functioning properly toxins will quickly build up in the body. The cat may become anemic and have electrolyte or blood pressure problems. Eventually the cat will be overrun by the toxic buildup. Kidney disease can be either acute or chronic.

Renal problems are more common in certain breeds of cats (Persians and Bengals) and in older cats. If you have an older cat you may want to start having him/her checked for CRF yearly as well as to make sure to feed him/her a diet especially made for good kidney and urinary tract health.

Acute Renal Failure
ARF occurs when there is an acute suppression of renal function. The fundamental unit of the kidney is the nephron and in ARF the nephrons suddenly die. In this case the kidney has no time to compensate for the damage. Such quick damage can occur due to ingestion of drugs or toxins (antifreeze), diminished blood flow to the kidneys from diabetes or blockages of the renal arteries, kidney infection, diabetes, infectious diseases, or trauma to the kidney. Acute renal failure is very serious. If left untreated the cat will die, however, if the cat is treated quickly and aggressively it is possible to restore some to all kidney function.

Chronic Renal Failure
CRF, in contrast, is a slow progressive disease in which the nephrons are slowly destroyed. In this case the kidney will compensate slightly for this loss; however, this is a long-term and fatal illness in cats. Causes of chronic renal failure may be a number of things from simple old age, to a genetic predisposition, to a tumor in the kidney. If your cat does have CRF you will need to look into how to keep the cat’s quality of life as a high as it can be for as long as possible. Cats can live for months to years with CRF with the proper treatment, medical attention, love and caring.

Keep in mind that cats can survive with as little as 1/3 of their kidney functioning. So by the time you notice a problem your cat may have undergone significant kidney damage. Thus, at the first sign of a problem take your cat to the vet and have him/her checked out.

Symptoms to look for:

  • Loss of appetite and weight
  • Increased thirst
  • Increased urination
  • Incontinence
  • Vomiting
  • Diabetes
  • High Blood Pressure
  • Bad Breath
  • Lethargy


Your vet will diagnose your pet by taking some blood and urine. Your vet will look at a blood panel for high levels of BUN (blood urea nitrogen), creatinine and phosphorous. In the urine your vet will look for any infection, loss of protein and the ability to concentrate (the inability to concentrate the urine is a good marker for renal problems). Your vet may also want to perform an x-ray or ultrasound to look at the kidneys themselves as kidneys in failure are usually shrunken and irregular in shape.

Treatment for renal failure usually is threefold. The first goal is to keep toxin (urea and creatinine) levels low. The best way to accomplish this is with fluid therapy and diet modification. The dietary modification will provide the cat with foods that produce less waste products upon digestion and the fluid therapy will help to flush out present toxins. Cats can either receive fluids intravenously or subcutaneously; the frequency of such therapy depends on the progression of the disease. Dialysis is also becoming more prevalent these days although it is still expensive and not available at all veterinary clinics. The second goal is to limit the levels of phosphorous in the body as this complicates renal failure. There are medications that bind phosphorous in the intestines, these are usually recommended. The third goal is to prevent stomach ulcers that may coincide with high levels of uremic toxins.

Depending on what secondary problems the cat is facing (anemia, high blood pressure) a subsequent course of drug therapy may also be prescribed.

Cats given a combination of fluid and drug therapy can live happy lives for anywhere from months to years, especially if the disease is caught early so keep an eye on your cats (especially older ones) and make sure to take your cat to the vet if there are any signs of renal problems.

Precautionary measures:

The best defense is a good diet. Make sure your cat eats a high quality food that is especially designed for proper kidney and urinary tract health (these diets will also be lower in salt, and phosphorous). Make sure that your cat is provided plenty of clean water daily. And if you have an older cat (8 years or older) you may want to take him/her to the vet once a year for a full check up, including a test for renal failure.