A cat’s diet typically will need to be changed at least twice during its lifetime. Kittens should be transitioned from a specifically-formulated growth diet to an adult maintenance diet somewhere between 6 and 12 months of age, to accommodate their changing nutritional requirements. Geriatric cats also have unique nutritional needs and should be fed a senior diet once they become “old.” When to make the transition to senior food is more art than science. The single-most important thing you can do to prolong the high-quality life of an older cat is to prevent obesity. Aging cats are less active than younger cats, and their diet must be adjusted accordingly to prevent excessive weight gain.
Older Cat's Needs
As cats age, their metabolism slows down. This lowers the cat’s dietary energy requirements. An animal that requires less energy, but continues to eat the same amount of food as it did as a youngster, will store surplus energy as fat and become overweight. Unfortunately, obesity is common in companion cats. Obesity puts a huge strain on an animal’s heart, bones and joints. Older cats need less dietary protein in their diet because they are slowing down in terms of activity at the same time that their metabolism is changing. In addition, the kidneys of aging cats have a diminished ability to deal with the waste products of protein digestion. Older cats usually benefit from a low-protein diet. A cat’s gastrointestinal tract loses tone with increasing age, so adding fiber to the diet may also be beneficial.
Older cats shouldn’t automatically be put on a senior food or a "light" diet, just because they reach a certain age. Diets formulated with the older cat in mind contain fewer calories, less protein and less fiber than adult maintenance diets. Animals who will benefit from a diet with these characteristics are those who have put on too much weight due to a decline in activity and those who suffer from frequent constipation. Other aging cats may not benefit from a “senior” diet. If an older cat is doing well on an adult maintenance diet, there is no reason to change foods, although the portions of each meal may need to be slightly adjusted.
Diets with the above characteristics may not be appropriate for all older pets, especially those who are still very active. Feed your cat according to its individual condition and energy level. This can best be determined by consulting with your veterinarian, to review your cat’s individual health and nutrient requirements.