Chronic renal failure is one of the most common conditions seen in the older cat. Signs which indicate that a cat may have renal failure include drinking more than usual, urinating frequently (large volumes) wieght loss and occasionally vomiting and anorexia.

Chronic renal failure occurs due to a progressive loss of functional renal tissue. This may occur due to one of many possible underlying causes. By the time signs of renal failure are noticed in a cat there may have been a loss of around three quarters of its normal kidney function. Obviously this is a problem which we see mostly in older cats; often these animals are over 10 years of age. Younger animals can be affected as well, especially if they have some kind of congenital problem which would impair their kidney function in some way.

Cats with renal disease are often observed to be drinking excessively. We often do not see healthy cats drinking very much, especially if they are fed on moist food, so any increase in drinking should be noted easily. As cats drink more they also have increased urinary output so they begin to need to urinate more frequently. Urine will be passed in normal to larger volumes, unlike in cystitis, where urination is frequent but the volumes are small. These signs of drinking and urinating more than usual should always ring alarm bells with owners because they are a sign which may occur in many serious diseases and your cat should be seen by a vet if he or she is doing this.

Cats with renal disease may also vomit, lose weight, not want to eat, become dehydrated and suffer from mouth ulcers. Sometimes cats with renal failure may become anaemic or have dental problems due to the metabolic effects of renal disease.

If your vet suspects that your cat may have chronic renal failure he or she may need to carry out some tests. Often your vet will take a urine and blood sample from your cat, both of which can provide useful information regarding kidney function. It may also be useful occasionally to perform an ultrasound examination or X-rays.

If your cat does have chronic renal failure there is much which can be done to help, although unfortunately there is no cure and the condition will get progressively worse over time. The treatment which can be given aims to increase your cat's quality of life and slow down the rate of progression of renal disease.

Access to water is very important to cats with renal disease and you should never restrict this for any reason. Your cat should always have a bowl of fresh, clean drinking water available. Many cats do not like the "chemical" smell of tap-water; to help this disperse you can store tap-water in a glass bottle in the fridge for 24 hours before use, this helps the chemical gasses come away and makes the water more palatable to cats. Some people do give their cats spring water but take care that you do not use something with a high concentration of minerals as this will not be good for your cat. Something like Evian is usually OK. Many cats prefer to drink running water from taps and if this is the case for your cat you should not discourage it. Commercial drinking fountains for cats are available and your pet may appreciate this.

Attention should be paid to the diet of cats with renal disease. The diet should be low in protein and minerals especially phosphorus. Of course cats still need protein in their diet but this should be a very high quality protein.

There are many commercial diets available on prescription which are formulated for cats with renal failure. In my view, cats with renal disease should not be fed a dry diet as they need plenty of water and some of this will come from their food if they are fed a moist type of diet.

Cats may sometimes be given vitamin B to help to compensate for the loss of vitamins which occurs in renal failure. Anabolic steroids may also help your cat. Often cats with renal failure also have high blood pressure and this can be treated by your vet if necessary. Occasionally i/v or subcutaneous fluids will be needed if your cat becomes too dehydrated. Some other treatments may also be necessary depending upon the clinical condition of your cat.

In the United States vets are performing renal transplants for cats with chronic renal failure. However, there are risks to both the donor and the recipient animal with this type of surgery and it also raises some very serious ethical questions since a healthy cat must be used to provide a kidney. This healthy cat must undergo surgery from which it does not benefit in any way and it loses half its own renal function into the bargain. Although the donor cats which are used are often strays which must then be homed by the owners of the recipient cat, it still seems ethically challenging to me.

Unfortunately chronic renal failure is a progressive disease, so with time (a few months or possibly years) affected cats become more and more unwell. Eventually despite all our best efforts it may be necessary to euthanase the cat in order to prevent undue suffering in their final days of life.

We have diagnosed your cat with Kidney failure

It is very upsetting when a pet has been diagnosed with a serious health condition such as kidney failure, especially when a cure is not available.

Procedures such as kidney transplants are not really an option for animals as they are for humans. However, there are several ways we can help improve not only your cat’s quality of life but help him/her live longer.

What causes kidney failure?
Chronic kidney failure refers to a condition whereby the kidney is no longer able to function efficiently and occurs when approximately two thirds of kidney tissue has been damaged.

The disease is most commonly seen in older cats and the gradual loss in functioning kidney tissue can often be attributable to the normal ageing process. In these cases, the progression of the kidney failure tends to occur over several months to years. There are also some more specific causes of kidney damage such as infections, cancers and various inherited disorders which can also potentially lead to kidney failure.

What are the symptoms of kidney failure?
One of the main functions of the kidney is to filter out toxins from the blood and remove them from the body in the form of urine. Being originally desert animals, cats have evolved to preserve body water by producing small amounts if very concentrated urine and so one of the early signs of kidney failure is that cats start to produce larger volumes of more watery urine. In order to avoid getting dehydrated, affected cats will be seen to drink much more water than normal.

As kidney failure progresses, the toxins which the kidney should normally remove from the body start to accumulate in the blood stream leading to symptoms such as appetite loss, nausea, lethargy, weigh loss, mouth ulcers, halitosis (bad breath), vomiting and diarrhoea.

How is kidney failure treated?
Once kidney tissue is damaged the body is unable to regenerate it and so treatment is aimed at helping your cat cope with its remaining kidney function and ideally minimize further damage.

Diets
Special diets are recommended to reduce the workload on the failing kidney. Often cats with kidney failure have a poor appetite and so warming their food to increase it aroma may help, as well as feeding little and often.

It is also important to make sure your cat drinks plenty of water since they have a much higher risk of becoming dehydrated. This can be achieved for example by having more water bowls around the house, using drinking fountains, flavouring the water or mixing small amounts of water into food.

Medicine
We have prescribed tablets which contain an ACE inhibitor medicine called Benazepril. This improves kidney function in cats with kidney failure and slows further progression of the disease. It has also been shown to improve the appetite and quality of life as well as prolong life expectancy.

It is important to remember that this medicine does not cure the disease and so must be given long-term in order for your cat to get beneficial effects. Usually the medicine is given once daily and can be given either directly in your cat’s mouth or with food.

Monitoring your cat at home
It is important that you monitor your cat closely especially for how much food and water they consume since the reduction in either of these can be a sign of the condition worsening. Other signs such as vomiting, lethargy or a pungent odour from the mouth should prompt further veterinary attention.