Kidney Failure in Cats

As commonly as people die of heart failure, cats die of kidney failure. It is the number one cause of death in cats as they grow older. The number two cause is cancer.
Cats are a desert animal, and because of this arid adaptation, their kidneys over-concentrate their urine throughout their lifetime. This excessive effort by the kidneys comes with a cost and that cost is the decline and loss of functional nephrons in the kidney parencyma. No loss of function is noticed physiologically until over seventy five percent of the kidney function is gone. The first stage of compensation by the patient is excessive water drinking. An owner notices the excess water consumption and usually sees the litter box filling up faster too, especially with clumping litter. The next stage is that the cat loses weight and eventually fails and becomes dehydrated. A visit to the veterinarian comes next.
Blood tests measuring the blood urea nitrogen and creatinine will reveal insufficient kidney function in the cat. Primary treatment includes initial diuresis and a change to a low protein diet like the Science Diet K/D. Home care fluid therapy may need to be included as an ongoing treatment to keep the cat flushed of lethal toxins that build up without extra fluid intake. Ultimately the cat will succumb to it's failing kidneys, but I have seen many do well for years on prescription diets and home care subcutaneous isotonic fluid therapy. A cat will live for more than twenty years if it doesn't get kidney failure or cancer. In my practice, I saw many cats over twenty years old and one that even made it to twenty nine!
Dr. Doug Ikeler www.drdougikeler.com