Causes of Chronic Renal Failure in Cats
Chronic renal failure (CRF) involves a long-term insult to the kidneys that causes them to gradually deteriorate, losing their ability to concentrate urine and remove waste products from the bloodstream. The reason cats get this condition isn’t well-understood, although advancing age is considered to be the biggest risk factor. It seems that as cats get older, their kidneys simply start to wear out. Most cases of chronic renal failure in cats happen when they are 7 years or older. Genetics almost are always involved, because certain cat breeds and family lines have an increased preponderance of chronic renal failure as composed to the normal domestic cat population. Other reported contributing factors include:
- Exposure to nephrotoxic poisons (nephrotoxins are substances that destroy kidney cells, which are called “nephrons”)
- Congenital kidney disorders (“congenital” means something that exists at birth)
- Prior episodes of acute renal failure
- Chronic urinary tract obstruction (narrow urethra, chronic infection, kidney or bladder stones)
- Drugs (especially nonsteroidal anti-inflammatory drugs [NSAIDs] and nephrotoxic antibiotics)
- Polycystic kidney disease (a common congenital kidney defect)
- Lymphoma (a type of cancer; also called lymphosarcoma)
- Infectious diseases (especially feline leukemia virus [FeLV] and feline infectious peritonitis [FIP])
- Exposure to heavy metals (mercury, lead, thallium)
- Abdominal trauma (especially when the pelvis is fractured and the bladder is ruptured)
A number of different kidney diseases can contribute to chronic renal failure in cats, including glomerulonephritis, pyelonephritis, tubulonephrosis, amyloidosis and tubulointerstitial nephritis. A veterinarian is in the best position to discuss these diseases with cat owners. Unfortunately, the cause of a cat’s chronic renal failure usually remains a medical mystery.
Preventing Chronic Renal Failure in Cats
Because the underlying cause of chronic renal failure is elusive, it is difficult to identify ways to prevent this disease. Most cases of feline CRF can’t be prevented, and unfortunately they are not particularly responsive to treatment. Many cats diagnosed with chronic renal failure can be managed with medication and supportive care for some period of time, but none can be cured. Companion cats – especially those over 7 years of age - should have an annual veterinary examination with blood and urine screening to monitor kidney function and the health of their other vital organs. Dietary management can also be helpful. There are a number of good commercial kidney diets that are available with a veterinarian’s prescription. Of course, free access to fresh water is always important, especially for cats with kidney problems. Cats that are known to have kidney disease in their family probably should not be used as part of a responsible breeding program.
Cats with chronic renal failure often show no symptoms of their condition for months or even years. Early diagnosis of CRF and conscientious supportive care can delay progression of the disease and help maintain the cat’s quality of life.