As dogs age, changes occur in the way their bodies function, so it makes sense that what they eat also might need to change. The following list of health issues might be more common in aging pets.
Decreased Immune System Function
Throughout a dog’s life, a process called peroxidation occurs. Peroxidation is a normal process that the body uses to destroy cells that outlive their usefulness and to kill germs, parasites, etc. This process, however, also can destroy or damage healthy cells. As your dog ages, the damage caused by peroxidation accumulates, which, in turn, increases the risk of certain problems, such as infections.
Antioxidants are naturally occurring nutrients that help maintain overall health by neutralizing the peroxidation process of cellular molecules. Some antioxidants, such as vitamin E, beta-carotene, and lutein, are naturally occurring nutrients.
Recent research sponsored by The IAMS™ Company found that dogs fed a diet rich in antioxidants such as vitamin E, lutein, or beta-carotene had improved immune responses and vaccine recognition. This might be especially important in senior dog care; IAMS research has found that as dogs age, immune responses can decrease.
More Frequent Intestinal Problems
Older 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 (e.g., diarrhea).
Feeding a diet containing fructooligosaccharides (FOS), a unique fiber source that helps nutritionally maintain healthy intestinal bacterial populations, promotes growth of beneficial bacteria. Beet pulp, a moderably fermentable fiber source, also helps maintain intestinal health by providing energy for the cells lining the intestine and promoting small, firm stools.
Different dogs show signs of aging at different times, and much of this variation is associated with size. Larger dogs generally appear 'old' sooner than smaller dogs. The table below lists the age at which various groups of dogs should be transitioned to senior foods, such as IAMS™ ProActive Health™ Senior Plus.
| 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 |
Like any companion or roommate, dogs — for all their love and cuteness—have habits we just don’t understand. One question dog owners often ask their pets: “Why? Why would you eat poop?”

When we polled* dog owners recently, most thought it was because a dog is lacking nutrients (49%), they’re anxious (43%) or they just think it tastes good (40%).
Dogs are significantly more likely to eat the droppings of another species (e.g., horses, rabbits) than their own.
We held our noses and got to the bottom of the issue with the help of some experts.
While those in our poll thought this was the number-one reason for the behavior, it has actually never been proven. “It’s a myth dogs eat poop because they’re seeking nutrients they aren’t getting. There’s no evidence to back this,” says
Opens a new windowDr. Jo Gale, BVetMed CertLAS MRCVS, Senior Manager, Global Science Advocacy at Waltham Petcare Science Institute.

According to
Opens a new windowDr. Tammie King, Applied Behavior Technical Leader at Waltham Petcare Science Institute, “It can occur where there is lack of environmental enrichment. You see this often in dogs who are kenneled and have a lack of opportunity to exhibit normal canine behavior.” So if you need another excuse to get out and play with your pooch, this is a good one.
Believe it or not, this is the main reason dogs eat poop. Dr. Jo Gale explains: “Dogs are scavengers by nature and use any opportunity to eat what they can, when they can. They consider it a ‘tasty snack.’” Dr. Tammie King adds that “[Dogs eating poop] is a learned behavior. They’ve done it, enjoyed it, and that behavior is repeated.”
We love our dogs so much that we’re willing to trust our best friends on this. Maybe we should come out with a line of doggie breath mints though. Hmm.

“Ingesting feces from any animal increases potential for ingesting parasites and pathogens,” cautions Opens a new windowDr. James Serpell BSc, Phd Professor of Humane Ethics & Animal Welfare at University of Pennsylvania School of Veterinary Medicine. He went on to say, “[It’s] not something humans should ignore, but it's not worth getting too excited about it.”
All the experts we consulted said that if your dog occasionally eats poop, it’s nothing to be overly alarmed by. Just keep an eye on the frequency and their overall health. And as always, make sure they’re getting a nutritious diet and plenty of exercise and attention. If you have any concerns contact your vet.
Despite dogs liking the taste of poop, we’re going to stick with the healthy range of more traditional flavors offered in all IAMS dog foods.
*Surveyed U.S. dog owners, age 18+
Sample Size: n=201
Fielded May 8 to May 10, 2020