Cats do suffer from kidney failure, it is not uncommon. As any veterinarian will suggest; keep a close watch on your cat and look for changes. When you observe these changes, consult your veterinarian immediately.
The first indication of renal failure in cats is increased thirst. Kidney disease, in the variety of chronic renal failure (CRF), is a frequent problem in older cats. Still, kidney failure can occur in cats as young as four years, but far more recurrently in much older cats. The most obvious sign is an increase in water intake and urination. A blood test should be done if you observe these symptoms, because there are quite a lot of conditions that can cause this. The increase in drinking and urinating in CRF is due to loss of the kidney's capability to concentrate the urine. The kidneys have a hefty reserve capacity, and symptoms of kidney failure are not seen until around 75% of kidney tissue is non-functional. Kidney failure is said to be the most common cause of death in older cats.
Laboratory tests are required to diagnose CRF. A blood test alone is as a rule not satisfactory; a urinalysis must also be taken at the same time the blood is drawn. Kidney disease is probably present when the cat is “azotemic” and the urine is not adequately concentrated. “Azotemia” means that there is an increase in particular compounds in the blood; in particular blood urea nitrogen– BUN–and/or creatinine. The measurement of urine concentration is known as Urine Specific Gravity (USG). If the feline’s USG is less than 1.035 and azotemia is there, then kidney function is atypical. BUN and/or creatinine may be high if the cat is dehydrated--widespread in cats who eat a lot of dry food, or during searing hot weather or after a taxing car ride. They may also be increased in animals on a high protein diet. As long as the kidneys are capable of concentrating the urine, small elevations in BUN and/or creatinine are generally not a cause for alarm.
Recent research advocates a link between vaccination for feline distemper and immune-mediated inflammation of the kidneys, which is believed to be the cause of CRF. Annual boosters for distemper are entirely unnecessary. Be sure to discuss all suggested vaccines with your veterinarian. A cat with kidney failure or kidney disease should not be vaccinated at all.
Continuing feeding of an all-dry-food diet is also alleged as a factor in Chronic Renal Failure. Cats' kidneys are very much efficient and adapted to life in the desert, where they would obtain most or all of their water from eating their prey. Cats eating dry cat food receive only half the water that the cats on a canned or homemade diet take in; this chronic dehydration can cause stress on the kidneys in due course. Dry diets also dispose cats to lower urinary tract disease (FLUTD, LUTD, FUS, stones, crystal, cystitis) for the reason that they force such a high degree of urine concentration. Chronic or frequent bladder disease may also be a cause in the development of CRF.
So keep an extra close watch on your feline each and every day. Cats are fragile creatures and depend on their human companions.