Kidney disease is a common condition of old cats. Although a dog is more likely to suffer heart disease, a domestic cat is more prone to degenerative diseases of the kidney.
The reasons for this are probably related to diet. The urban dog is prone to obesity. Often it is under-exercised and overfed. And although commercial dog foods are well balanced they are usually supplemented with high-energy table scraps and snacks.
On the other hand, most cats are fastidious and usually tend to exercise so they are not so likely to be overweight. Their preferred diet, however, is very high in protein.
It is the excretion of the waste products from the metabolism of this fraction of the diet that is the responsibility of the kidney cells.
As these cells age or their blood supply is impaired, they eventually cease to function. They cannot be repaired or replaced, as some liver cells are, and it is the animal’s compensatory measures that are the first obvious signs of kidney disease.
Occasionally the onset of symptoms may be dramatic when large numbers of kidney cells are damaged at once. This can happen as a result of the spread of an acute infection from a badly infected wound.
More often the signs are much less dramatic. The cat begins to become more fussy with its food. It starts to eat less and although apparently hungry will leave its food after only a few mouthfuls.
It usually has begun to drink more water and this may go unobserved until the cat starts leaping into the sink or the bath to lick the moist surface. It starts to lose weight and its skin becomes dry and the coat no longer is smooth and shiny.
As the disease progresses the cat becomes less lively, preferring to sleep in a secluded spot. It develops a brownish scale on its teeth and its gums bleed easily. The breath is unpleasant and can have a distinct smell of ammonia.
In the advanced stage of the disease, toxic products of protein and fat metabolism accumulate in the blood and the cat refuses all food — many start to vomit — and wishes only to hang over its water bowl.
Treatment of kidney disease is difficult as it is usually only begun after considerable numbers of kidney cells are already damaged.
Attempts to reduce the overall protein level of the diet is not usually successful as most low-protein foods are unpalatable to the cat.
If it is keen on milk, increased amounts can be fed as this is a good source of energy without high-protein levels. Liver and kidney should be avoided, and in general, white meats are preferable to red meats. Of course, any active infection must be treated with antibiotics.
Prevention of kidney disease is well-nigh impossible. It is a degenerative condition and an animal ages one of the body’s systems must eventually fail.
Premature damage to kidneys may occur because of infected wounds — prompt treatment of cat bites lessens such a risk — and the desexing of male cats.
Supplying a supplement, which contains vitamins, minerals and anabolic steroids, to an older cat may also be of value in delaying the onset of kidney degeneration.