Dogs hit maturity around 7 years of age (5 years for larger dogs). It's not uncommon for them to live as long as 15 years. As your pet enters his golden years, his activity level might slow down and common conditions such as arthritis, diabetes, and kidney disease may arise. “It is so more important to monitor the eating habits of older pets,” stresses Tom Carpenter, DVM, president of the American Animal Hospital Association. “Generally, older pets do not need as much protein, sodium, and phosphorus. But your veterinarian needs to address this for your individual pet,” he says, adding that semiannual vet visits are recommended for an older animal.
Some mature dogs are prone to obesity. To test whether your dog is at a healthy weight, move your hands along his sides. If you can feel his ribs (but don't see them), he's doing okay. But if you feel a fat covering, or you visibly notice a rounded abdomen, he might be overweight. Exercise is still important for a senior dog, and if he's gained weight, you want to look for a low-fat weight-control food that contains vitamin-rich fish oils (IAMS™ ProActive Health™ Mature Adult is one good choice).
Other mature pets can become finicky eaters and lose weight as they age. 'Very old pets may actually need a more calorie-dense diet,' Carpenter says. Older dogs can lose their sense of smell and have a harder time chewing their food. To make mature dog food easier to eat, you can top their dry food with room-temperature wet food.
If your dog is gaining or losing a lot of weight, slightly decrease or increase his daily feedings. A sudden change in weight or appetite might be a sign of disease, so you should check with your vet. Water is also essential. 'Older pets are at a higher risk of dehydration,' Carpenter says. Provide a clean bowl with fresh water at all times.

In the past, veterinarians recommended diets for senior dogs largely based on the nutritional management of diseases common to the aging process. Research, however, has shown that special nutrition can help manage body-condition problems in aging dogs, such as obesity and loss of muscle mass. Senior dogs also benefit from special nutrition to help maintain bone and joint health.
Learn more about how you can help your senior dog manage common health issues associated with aging.
Senior dogs tend to gain weight, despite consuming fewer calories, due to changes in their metabolic rate. Therefore, they can benefit from eating a diet with reduced fat levels and lower caloric density than adult maintenance foods.
Recent IAMS™ research in dogs also indicates that L-carnitine — a vitamin-like compound made in the body from the amino acids found in red meats, fish, chicken and milk — can help reduce weight in overweight dogs by escorting fat into cellular mitochondria where it is turned into energy.
Protein is the building block of muscle tissues. It is important for maintenance of muscle tissues, muscle strength and mobility. Recent research conducted by The IAMS Company has shown that senior dogs that eat a higher-protein diet better maintain muscle protein stores. By providing optimal protein levels from muscle maintenance, we can help senior dogs continue being physically active.
This research is contrary to conventional opinion that senior dog foods should contain lower protein levels than adult maintenance formulas to avoid progressive decrease in kidney function. However, senior dogs fed a high-protein diet had stable renal function and a lower death rate than dogs fed a lower-protein diet.*
During the aging process, cartilage between joints often begins deteriorating. Nutritional management can help maintain healthy bones and joints and mobility in dogs in several ways:
Some pet-food manufacturers have endorsed reduced levels of calcium and phosphorus based on the belief that excesses of these minerals are harmful to the kidneys. However, research has shown that no damaging accumulation of calcium or phosphorus was found in the kidneys of older dogs fed diets containing maintenance levels of calcium and phosphorus for four years.*
* Finco, DR. “Effects of aging and dietary protein intake of uninephrectomized geriatric dogs.” American Journal of Veterinary Research; Vol. 55, No. 9. Sept. 1994.
