Chronic kidney failure ('renal failure') is one of the most common diseases seen in older cats. Studies suggest that approximately 1 in 5 cats over 15 years of age is affected. This is a progressive disease, that is, it cannot be cured and will gradually get worse. With the right support and treatment, however, the rate at which it progresses can be slowed and affected cats can be given a better quality of life.
Whilst there are several recognised causes of kidney disease (including tumours and infections), in most cases the cause is never established and the aim of treatment is to reduce the symptoms rather than tackle the cause.
The kidneys play a vital role in removing toxins from the blood (expelling them in the urine) and in maintaining the correct balance of water in the body, as well as the levels of certain salts and minerals. Where the kidneys are not working effectively cats may show signs including reduced interest in food, weight loss, listlessness, excessive water intake, dehydration, smelly breath and a loss of coat condition. These signs can be seen with other diseases too, so to confirm a diagnosis of renal failure a blood sample and urine sample are usually needed.
Altering your cat's diet is one of the key ways of managing kidney disease. There are now a number of prescription diets designed specifically to support cats with this condition. Amongst other things, these diets are low in protein (which reduces toxin formation) and low in phosphate. It is also very important that cats with kidney disease drink plenty, as they are unable to concentrate their urine, so can become dehydrated quickly by losing too much water when they urinate. At the time your cat is diagnosed with kidney disease he/she may need to stay with your vet on a drip to ensure good hydration.
Finally, there is good evidence that use of a certain class of drug called 'ACE-inhibitors' can help treat cats with kidney disease, so your vet may prescribe regular tablets for your cat.