Feeding an aging cat

Cats today live longer than the cats of 30 or 40 years ago. Back then they only rarely reached 20 years and more; now it is a commonplace. Several things have brought cats to such long lives, above all the defeat of a good many feline ailments, and of “feline melancholy” (depression) in particular. All the same, how long cats live depends first of all on the improvement in cat food.

Set beside the unbalanced food cats used to get, made up mostly of scraps from the kitchen, they now eat food prepared specially for them. The needs of cats of different ages and the rations that suit them have been studied closely in recent years, and as a result such things as a shortage of calcium in the animal have become a thing of the past.

The dietary needs of ageing cats have become a subject of study in their own right. An ageing cat has its own diet, just as an ageing person does. There is little published on the subject, but we can extrapolate from what is known about the feeding of other species, and from our own experience, to work out what a cat of “pensionable age” requires.

Let us go through a few principles worth keeping to if your elderly cat is to have a happy life. The first principle: keep the cat from growing fat. Animals that overeat suffer from high blood pressure. They are prone to illness, which naturally shortens their lives. The illnesses in question are chiefly these: diabetes, arthritis, heart disease, liver disease, disease of the respiratory tract, and cancer. And that is only a small part of the list. To feed a cat its fill at this age amounts to killing it — killing it with kindness.

To keep it from growing fat you have to weigh the cat, because a slight change in weight can very soon turn into a considerable one. While your cat is young and in its active years, keep an eye on its weight, and try to hold it at one and the same weight through every stage of its life. Bear in mind that neutering a tom or spaying a queen substantially reduces the portion needed to maintain that weight.

The second principle: the diet must be balanced. A shortage of such substances as calcium, phosphorus and taurine leads to damage that will later be difficult, and sometimes impossible, to put right.

Avoid overfeeding. An excess of the necessary substances can tell on a cat’s health quite as badly as a shortage of them. Too much vitamin A or D, for instance, brings about irreversible changes that will shorten the animal’s life. If your cat’s food is well balanced, it needs no artificial supplements at all. Giving supplements on top of an already ample diet may well lead to serious trouble later on.

The last principle: from kittenhood onwards, feed your cat so that it grows used to two or three well-balanced foods, and then leave the arrangement alone. Do not let the cat gorge itself on fish and liver, which are not balanced foods.

Now that we know how to feed young cats, let us turn to the particular changes that ought to be made to the ration of a healthy cat as it begins to age. But how is one to tell that a cat has begun to grow old? As with people, the onset of old age depends on a great many things, and it is hard to name an exact date. Some animals stay lively past the age of 10, while others go sedentary a good deal earlier. I cannot tell you the day and the hour on which your cat becomes a “pensioner”, but as a rule it happens between 12 and 15 years.

Some of the signs that point to old age in a cat: an unwillingness to play, sleepiness, and a tendency to put on weight even though you have not increased the ration. As for deciding whether your cat is old or not, your own impressions will tell you unerringly.

The moment your cat begins to “feel its years”, you should make some changes to its ration. The first is to reduce the amount of food it eats, since your cat no longer spends the energy it once did. A young cat spends 40 kilocalories of energy per pound of body weight a day. An old cat spends a good deal less — 30–35 kilocalories per pound of body weight a day. So a healthy 4-kilogram old cat should be eating a hundred grams of food a day less than a young cat of the same weight.

Most cats prefer a large amount of fat above all, since it makes the food taste better while at the same time raising the calorie count. To keep an old cat from growing fat, the owner has either to reduce the amount of food or to give food with less fat in it.

If you fed your cat on free choice while it was young, you will now have to give the practice up. Feeding without a system is always the road to overeating in an ageing cat. Reducing the amount of food will do your cat no harm, though you may want to let it understand that this is the better food, so as to soothe its pride.

If you hold that a cat should eat as much as it wants, then you will have to turn to food with fewer calories in it. There are several ways of doing this. The first is to reduce the fat in the food and increase the fibre; the second is to reduce the moisture. The second way does not work, because the energy in dry food is not reduced, and the cat goes on satisfying itself with the same amount of dry food as before. Cats have to fill the stomach with a certain amount of food, and that is an important part of feeling fed.

Some foods for older cats have exactly this quality — little fat and a great deal of fibre. Prescription Diet for cats, put out by the Hill’s animal food company, is one of them. When you are choosing food for a cat, look for boxes that carry a leaflet saying the food is 95% fat-free. In cat food as in human food, that means the fat content is 5%. A tinned product, say, contains 75% water and 5% fat, so those 95% without the fat hold a further 20% of dry filler. A diet like that will not do, because 40% of the calories still come from fat. It may do for a young and active animal, but for an old cat it will not.

What about protein? Many foods for older dogs contain a reduced amount of it. That does not mean a healthy young dog needs less protein. Since cats require more protein than dogs, cat food is 30% protein on a dry basis. Research has not shown that ageing cats need less protein in their food than young ones, so owners should not reduce the protein content of cat food.

As for minerals, the skeleton of an ageing animal is no longer growing and developing as a young animal’s is. On the other hand, phosphorus and calcium are absorbed less well than in a young animal. There is therefore no need to change the amount of phosphorus and calcium in cat food; better to leave it at the same level as for young animals — about 0.6–0.7% on a dry basis. The magnesium content stays the same as well, 0.1% or less on a dry basis, to reduce the chance of stones forming in the bladder. As for salt, a low level of it is always to be recommended. Cat food contains 0.4–0.5% salt on a dry basis. On the other hand, so long as the cat has fresh water in plenty, a high salt content in the food presents no danger.

The amount of minerals and vitamins an old cat needs is the same as for a young one. As was said in connection with young animals, old cats must have enough nourishing food, vitamins and minerals included.

On the strength of all of the above, we conclude that there is no sense in changing an adult cat’s ration sharply, with the amount as the only change. A drop in activity brings a gain in weight after it.

Some age-related illnesses can be kept in check by changes of diet. Among them are chronic renal failure, heart failure, uraemia and cancer.

The illness that strikes elderly dogs — renal failure — drew the attention of researchers precisely because it can be treated with a special diet. Treatment by diet consists in restricting protein, phosphorus and salt, and raising the calorie count. The method has prolonged the lives of a great many canine patients.

The same dietary principles are used with cats suffering from renal failure. Retention of phosphorus, with the fall in blood calcium that follows it, leads to the destruction of bone; reducing the phosphorus content is therefore a logically justified step. Reducing salt is also recommended, as a way of guarding against high blood pressure. Protein cannot be excluded for cats as it can for dogs, because their need for protein is higher. A small amount of protein, together with a raised calorie count (animal supplements), will help the cat bear these restrictions. Diet food for the animal can be obtained through your vet.

The signs of kidney disease are excessive drinking, increased output of urine, anorexia (refusal of food), vomiting and depression. If these signs appear in your cat, you should call the vet as soon as you can. A quick change of diet can add a good deal to your cat’s life.

Blockage of a heart valve, known also as cardiomyopathy, often occurs in cats through a shortage of taurine. Unfortunately, some ageing cats eat food without taurine in it, which helps the disease along. In heart failure a salt-free diet is of use. This special diet can be recommended by your vet. The signs of cardiomyopathy include a chronic cough, depression, and a tendency to tire quickly. Your cat must be shown to a vet at once if such signs appear.

Feline urolithiasis — one of the forms of the urological syndrome — occurs in old and young cats alike. A diet with too much magnesium in it, which also brings on the urological syndrome, is met with more often in middle-aged and old animals. A diet with the magnesium restricted has to be given to the cat all its life. If a cat with the complaints described above begins to recover, the diet should nonetheless be kept up, with a reduced amount of protein. The diet should also include a set of minerals that helps the stone to dissolve.

The symptoms of feline uraemia include painful, infrequent urination and blood in the urine. Complete fouling of the urinary ducts is a serious threat to life. If you suspect anything of the kind in your cat, you need to go to the vet immediately. Once the blockage has been dealt with, the vet may prescribe a diet that helps the stones to dissolve.

Cancer is met with more often in old animals. A new method of treating it by diet, in people and in animals alike, has appeared. Features of the food such as a raised fat content can have a good effect on the animal’s health. Recent research makes it possible to cope with this disease in animals and in people both.

Further research is needed to master the feeding methods that will prolong the lives of many cats. I hope that the advice published in this article will help you feed your cat in a way that gives it a long and happy life.