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.

The Association of American Feed Control Officials (AAFCO) was formed in 1909 to establish a framework for uniform regulation of the feed industry. Although not a government agency, AAFCO operates within the guidelines of federal and state legislation including laws administered by the Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA).
AAFCO establishes standards or models for regulations aimed at ensuring that manufacturers provide clear, accurate, and consistent information about animal feed, including pet food.
Every year AAFCO issues an official publication called the AAFCO Manual. This manual, in addition to listing ingredient definitions and feed terms, addresses labeling issues such as label format, ingredient lists, nutrition claims, and guaranteed analysis.
These model regulations are different than laws. However a large number of state governments have adopted AAFCO pet food model regulations into state law.
The “AAFCO statement of nutritional adequacy or purpose,” also called a “nutrition claim” or “complete and balanced statement,” identifies which life stage and/or lifestyle the product has been approved for. Under AAFCO regulations, this statement must be substantiated by the manufacturer.
AAFCO recognizes three methods for substantiating the claim:
AAFCO has outlined very specific protocols, or guidelines, for conducting feeding tests. The protocols specify test criteria including such things as:
Each life stage has its own protocol. Life stages are the same for both dogs and cats and are defined as:
A pet food with an 'All Life Stages' claim can be used from weaning through adulthood. This claim is considered an unqualified (absolute) representation of nutritional adequacy. If substantiated through feeding trials, the protocol for gestation/lactation and growth must be performed sequentially, using the same group of animals.
AAFCO regulations state that specific wording must be used when a diet is intended for special nutritional or dietary needs that require the involvement of a veterinarian for diagnosis, management, and follow-up.
Understanding the AAFCO statements for nutritional adequacy can help customers choose a high-quality diet that provides complete and balanced nutrition for the appropriate life stage of their dog or cat.