Q. Kidney problems seem to be very common in older cats. I feel that such cats are often taken to a vet for euthanasia far too soon. At what stage in this illness would you feel that it is advisable to euthanase the cat?

The clinical signs of this disease are: weight loss; polydipsia/polyuria (excess thirst and drinking of water and excess passage of urine); reduced appetite with possible vomiting in the later stages; anemia; reduced kidney size; uremia (increased levels of urea in bloodstream and its excretion through the mucous membranes of the mouth, stomach and gut which can result in mouth ulceration, nausea and diarrhoea);dehydration due to loss of control of fluid balance in the body. These symptoms will be mild at first but will get progressively worse as the condition progresses. 

They can be controlled to some extent through controlling the diet, increasing water intake and supplying vitamins. Low protein diets using protein of high biological value (chicken, white fish, egg, milk, cheese etc.) which lead to less urea production and increased consumption of water to compensate for fluid losses help to keep many of the clinical symptoms at bay for quite a long time. However, a stage will inevitably be reached when the cat's own fluid balance mechanisms will fail and he/she will become dehydrated. 

Loss of appetite is also a big problem and the cat's own body tissues will be broken down to supply the calories the cat needs to function. This leads to severe weight loss. At this stage, a few days on a drip with B vitamin injections daily can pull the cat back from the brink and allow him/her to continue for several more months. There are also steroid injections which can help the cat preserve his/her body weight so long as he/she is still eating a reasonable amount of food. 

Deciding if and when to euthanase such a cat can be quite a difficult decision to make. It must be made by the owner in consultation with the cat's vet. Diagnosis of chronic renal failure should not necessitate any sense of urgency, though it is a progressive disease with very poor long term prognosis. Until the later stages when total kidney failure occurs, the cat can live a normal life and suffer very little if any discomfort. In the later stages, blood urea tests are a good indicator of the degree of kidney function. The cat will need hospitalisation for a couple of days every few months towards the end to restore his/her fluid balance. Or it may be arranged to take him/her in each morning and home each evening. 

A stage will finally be reached when the cat will lose all interest in food and drink and become dehydrated and severely depressed. If he/she fails to respond to a drip and becomes progressively more depressed, nauseous and dehydrated; it will become evident to both owner and vet that the stage has been reached where the quality and dignity of life is at an end and euthanasia may be the only alternative. I must add that the level of care and interest of the owner is a vital factor in prolonging such a cat's life. The owner must also co-operate with veterinary advice regarding diet, fluids etc. and must be able to monitor changes in the cat's demeanour, appetite etc. that may warrant further veterinary intervention. 

It can be very rewarding for a caring owner to help extend the life of a much loved cat by quite a considerable time, and it certainly eases the sense of loss and sadness when the end inevitably comes if one has nursed an animal along and given it the best possible chance to live on in comfort after the diagnosis of a terminal illness.