Unlike larger-breed dogs that are considered mature at age 5, medium-breed dogs are usually called mature or senior at age 7. By this time, their nutritional requirements are changing. You can help keep your medium-breed dog active, happy and healthy with a specially formulated mature or senior diet that delivers highly digestible, enhanced nutrition.
Your dog might be aging in a number of ways. He may have a dull, dry coat and flaky skin, declining activity or weight gain, decreased immune system response, more frequent intestinal problems, joint stiffness and a loss of lean muscle mass. It’s true that a mature or senior dog generally needs fewer calories, but to address special mature or senior concerns, your dog still needs high-quality protein and carefully balanced nutrients.
What your medium-breed dog needs is a high-quality, balanced maintenance food formulated for his changing metabolism. Look for options with these age-essential dietary components:
These ingredients are the keys to mature or senior nutrition whether you feed dry or wet dog food or give your dog treats.
Older, less active dogs are prone to weight gain. Controlling your dog’s weight can help minimize health complications such as diabetes or joint stress. Your dog can benefit from a weight-control diet with these key characteristics:

Providing dogs with vitamins, minerals, and other nutritional components is important to their health and well-being. The best way to do so is by feeding a high-quality complete and balanced diet. Supplementing dog food often upsets the balance and may lead to a variety of health problems.
People supplement their dog's diet for different reasons. Some of these reasons might include:
It is important for concerned pet owners to realize that a quality dog food is carefully formulated to meet the caloric needs of the animal. In addition, the food provides the essential amino acids, fatty acids, vitamins, and minerals specific to the nutritional requirements of dogs. Quality foods are complete and balanced for a specific life stage or lifestyle. By adding table scraps or other supplements, the delicate nutrient balance can be disrupted.
The interaction between different minerals is very complex. Fortunately, this is an area of nutrition that has been the focus of extensive research throughout many years. Research has shown that not only are the individual levels of minerals in a diet important, but so is the proper balance. An excess of one mineral may affect the absorption of a second, and lead to a deficiency in that second mineral.
One common supplement is feeding additional meat. However, because meat contains 20 to 40 times more phosphorus than calcium, adding meat to a balanced diet will upset the calcium to phosphorus (or Ca:P) ratio, which is important for proper bone development and maintenance. This may prompt the animal's body to absorb calcium from the bones in order to reach the right balance. This is often the case in older animals that experience tooth loss due to the resorption of bone from the lower jaw. Ca:P ratio should range between 1.1 to 1.4 parts of calcium for each 1 part of phosphorus.
Excess amounts of calcium have been associated with several bone diseases affecting growing puppies. Owners of large-breed puppies in particular believe that their puppies require extra calcium for proper development of large bones. Adding yogurt, cottage cheese, or calcium tablets to the pup's diet will only upset the body's delicate mineral balance. Remember that large-breed puppies will consume more food and receive the calcium their bodies need by eating the recommended portions. The best way to support a normal growth rate is to feed growing dogs adequate—but not excessive—amounts of a balanced diet, using a portion-controlled regimen.
The Association of American Feed Control Officials (AAFCO) regulates the pet food industry and has established certain nutritional requirements for dogs and cats. These requirements are published annually in the AAFCO Manual. Only pet foods that have met the strict testing criteria established by AAFCO can carry the 'complete and balanced' statement on the label.