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
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 |