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:

As your dog matures, his body functions change. He might have decreased immune-system function, deterioration of skin and coat quality, and more frequent intestinal problems. So it makes sense that what a mature dog eats might also need to change.
Throughout a dog's life, a process called peroxidation occurs. This is a normal process the body uses to destroy cells that outlive their usefulness and to kill germs and parasites, but this process also can destroy or damage healthy cells. As a dog ages, the damage caused by peroxidation accumulates and, in turn, increases the risk of certain problems such as infections.
Antioxidants are naturally occurring components in the body (but also can be acquired through diet). They help maintain overall health by neutralizing the peroxidation process of cellular molecules.
Research sponsored by IAMS™ found that dogs fed a diet rich in antioxidants such as vitamin E had improved immune responses and vaccine recognition. This might be especially important for mature/senior dogs, because IAMS research has found that, as dogs age, immune responses can decrease.
Eating a complete and balanced diet with omega-3 fatty acids, such as those found in vitamin-rich fish oils, also helps rejuvenate dry skin and develop a healthy, lustrous coat.
Aging dogs might have higher numbers of unfavorable bacteria and lower numbers of beneficial bacteria in their intestines, which can result in clinical signs of gastrointestinal problems (such as diarrhea). A diet with a moderately fermentable fiber source such as beet pulp can help maintain intestinal health. Beet pulp provides energy for the cells lining the intestine and promotes proper stool formation.
Different dogs show signs of aging at different times, and much of this variation is associated with size. Larger dogs generally appear mature/senior sooner than smaller dogs. The table below can show you when your dog should start a mature diet with a food such as IAMS ProActive Health™ Mature Adult.
Dog Weight and Transition to Mature/Senior Foods
| Weight Range | Age to Begin Transition |
|---|---|
| More than 90 lbs | 5 years |
| 51 to 90 lbs | 6 years |
| 21 to 50 lbs | 7 years |
| Up to 20 lbs | 7 years |