We have asked a famous specialist-dietitian, an expert of "Cat Fancy" magazine Francis Calfers to tell about the diet of aged animals.
Contemporary cats live longer than that 30 and 40 years ago. At that time cats scarcely live up to 20 and more; and now it's an everyday occurrence. Several factors resulted in such a long life in contemporary cats, first, this the victory over many cat diseases, and "cat spleen" (depression) in particular. But still the period of cat life first of all depends on improvement of cat food.
In comparison with badly balanced food cats have been getting earlier that consisted mainly of kitchen leavings, today cats eat a specially made food. Cat demands of different age and their diet have been studied well in last years. As a result, such events as shortage of calcium in the animal organism have gone into remote past.
Food requirements of aged cats have become a subject of special research. Aged cats have their own diet, as well as aged people. Though there are little publications on this item we can extrapolate information about nutrition of other species of animals as well as our own experience to determine demands of cats of "pension age".
Lets discuss some principles that one must keep to provide a happy life to your aged cat. The first principle: restrain a cat from overeating. Animals that overeat, suffer high blood pressure. They are disposed to diseases which of cause reduce their age. In general this diseases include diabetes, arthritis, heart and liver disorders, disorders of respiratory tract and cancer. And this is a mere part of different diseases. To feed a cat fill in this age is equal to a murder, "a murder with kindness".
To escape from obesity one should weigh his cat, because a slight weight alternation may soon lead to its' considerable change. Whilst your cat is young and in "active age", control its' weight, try to keep invariable during all life cycles. Mind that after castration a cat needs a lesser portion of food to support its' weight.
The second principle: a diet should be well balanced. Shortage of such substances as calcium, phosphorus and taurin leads to pathological alternations that are hard and sometimes impossible to cure.
Try to avoid from overfeeding. The deficiency of essential nutrients as well as their excess may have a pernicious influence on a cat health. For example, vitamin A or D abundance causes irreversible changes that may reduce the animal age. If your cat food is well balanced it doesn't need any artificial addings. If you give your cat an artificial additional food along with an abundant feeding this may lead to serious problems in the future.
The last principle is that from early years one should feed his cat so as it get used to 2-3 kinds of food that are well balanced and one should not change that. Don't allow your cat to eat too much fish and liver, for this food is not well balanced.
Now that we know how to feed young cats lets concentrate on specific changes that should take place in ration of healthy cats when they begin to grow old. But how to determine a cat has begun to grow old? The beginning of old age both in cat and in people depends on many reasons and it's hard to point the exact date. Some animals stay active at age of 10; others may become motionless very much earlier. I can't tell you the day and the hour when your cat will become a "pensioner", but as a rule this happens between 12 and 15 years.
There are some signs showing your cat is in years: it doesn't want to play, often looks sleepy, and a tends to put on weight even if you doesn't increase its' ration. After all, as for how to determine if your cat is old or not, your own impressions will prompt this without fail.
At that very moment when your cat begins growing old you should somewhat improve its diet. First, reduce the amount of food because your cat doesn't spend so much energy as earlier. A young cat consumes 40 kilocalories per pound of its weight daily. Energy costs of an old cat are far less: 30-35 kilocalories per pound of weight daily. So? A healthy old cat of 4 kilograms should eat 100 grams fewer than a young cat of the same weight.
Most cats are generally fed with food containing much fat because this improves its gustatory quality, but at the same time this increases the amount of calories. To avoid obesity in an old cat, a holder should either reduce the amount of food or give his cat food containing less fat.
If you used to feed your cat as you wanted when it was young, now you should refuse this practice. Irregular feeding is the very way to obesity of an aged cat. The decrease of food ration will not bring harm to your cat, besides you may give it understand that this is the best food to assuage its self-esteem.
If you support the idea that a cat should eat as much food as it wants, you should give turn to food less rich in calories. This may be done in several different ways. First way is to reduce the amount of fat and to increase the amount of cellulose in food you give to your cat. Second is to reduce the amount of water. The latter is ineffective because the energy supply in dry food stays as previous, and cat anyway needs the same amount of dry food as before. A cat should fill its stomach with a definite amount of food and this is an important factor of satiety.
Some kinds of food for cats in years are remarkable for that they contain less fat and much cellulose. In particular, remember "Instructions for Cat's Diet" by the Hill Company specialized on sale of goods for animals. While choosing a food for a cat, look for boxes provided with a list indicating that this food is 95% skimmed. Both as for human and cat food this means that it keeps 5% of fat. If canned food contains 75% of water and 5% of fat, then these 95 percent without fat contain another 20% of dry filler. This food doesn't fit, since 40% of calories still fall at fats. Such diet may fit a young active animal but not an aged cat.
What about protein? Most kinds of food for aged dogs contain reduced amount of protein. This doesn't mean that a young healthy dog needs reduced amount of protein. As long as cats require less protein than dogs cat's food includes 30% of protein if in dried state. Studies haven't confirmed that aging cats need smaller amount of protein then young ones, thus holders shouldn't reduce the amount of protein in cat food.
As for minerals, the skeleton of aging animal doesn't grow and develop. On the other hand, phosphorus and calcium are assimilated worse than in young animals. Thus, holder should not change the amount of phosphorus and calcium in cat food but keep it at the same point as for young animals - about 0,6 - 0,7 % of dry substance. The same referrers to amount of magnesium for it should be left the same, about 0,1% of dry substance, or even less - to prevent formation of kidney stones in bladder. As for salt - a low level in food is flatly recommended. Cat's food includes 0,4 - 0,5 % of salt in dry substance. On the other hand, high amount of salt in food represents no hazard until cat has quite enough water.
The amount of minerals and vitamins for aged cat is the same as for a young one. As it was pointed in the case of young animals, old cats should have enough nourishing food rich in vitamins and minerals.
The conclusion of everything said above is that quick change in a diet of a mature cat has no sense, except for reduction of its quantity, because the decrease in activity causes the increase of weight.
One is able to control some disorders that accompany the process of aging, changing animal diet. These disorders include chronic kidney deficiency, heart deficiency, uremia and cancer.
Kidney deficiency in aged dogs attracts researches' attention by the very fact that it can be treated by a certain diet. This treatment includes reduction of protein, phosphorus and salts in food along with increase of calorie content. This method has already prolonged life of many dogs.
As for cats suffering kidney deficiency the principles in diet are the same. Conservation of phosphorus together with reduction of calcium in blood leads to bones destruction. Thus the reduction of phosphorus in diet is a reasonable step. The reduction of consumption of salts to prevent high pressure is recommended as well. Exception of protein can't be applied to cat diet as it is for dogs because of high necessity in protein. Small amount of protein along with increase in calorie content (food addings) help a cat bear this restrictions. A dietetic food can be obtained through your veterinary.
The signs of kidney disorders are excessive consumption of water, increased urination, anorexia (food rejection), vomiting and depression. If your cat shows this signs you should call a vet as swiftly as possible. A quick change in diet may considerably prolong your cat age.
The occlusion of mitral valve, also called cardiomyopathy, is often caused in cats by a deficiency of a taurin in their diet. Unfortunately some aging cats consume food without taurin and this promotes the disorder. A salt-free diet can be useful in a case of a heart deficiency. Your veterinary may recommend this special diet. The disease characteristics are chronic cough, depression and tendency to get tired easily. Your cat should quickly be taken to a vet if this signs have appeared.
Cat urolithiasis as of one of urological syndrome forms occurs both in aged and young cats. Diet that includes magnesium and causes urological syndrome occurs in mature cats and aged animals. One should put for all its' life a cat on a diet that includes enough urea. If a cat displaying all said above symptoms begins to put on weight one should keep the same diet though reduce the amount of protein. Besides, a diet should include a number of minerals promoting dilution of kidney stones.
The symptoms of cat's uremia include painful and infrequent urination and blood in urine. Total contamination of urethras represents a serious threat for life. If you suspect some of these phenomena in your cat you should immediately consult to a vet. After removing of contaminating elements a vet may prescribe diet that contributes to stones resorption.
Cancer first of all meets aged animals. A new method to treat both people and animals by means of certain diet has recently appeared. Such food characteristics as increased fat-content may have a positive effect on animal health. The results of latest researches allow one to cope with this disease both in animals and people.
Supplementary studies are required to understand the method of feeding that will prolong life of many cats. I hope that advices published in this article will help you feed your cat in such way as to guarantee it's long and happy life.
Translated by Tatiana Karpova (Moscow)
(MSU, Biology faculture, Dep. zoology and ecology).