Why Do Dogs Eat Poop?


Why Do Dogs Eat Poop?

I remember the first time I saw our dog, Bogart eat poop.

We went for a walk in farm land, and boy, was he in poop-eating heaven; cow poop, horse poop, I don’t know what poop. I was mortified. Would I ever be able to let him kiss me on the face again?

This was back in 1980’s, before I started feeding raw, meat-based diets with vegetables and before I had any understanding of the role of gut microbes in dogs’ health and behaviors.

I spent years trying to figure out why Bogart, and, as I learned, perhaps most dogs, eat poop.

Until recently, I concluded there are many reasons including obtaining calories, nutrients, and enzymes that highly processed dry foods do not contain. However, these nutrients were a vital part of their ancestral diet.

Recent science has suggested another reason. 1

Like why dogs eat grass, I think the dog’s gut microbes play a major role. Dogs eating sterile diets and even raw diets without vegetables or other roughage may need to eat poop for the microbes. Their gut microbes almost command it!  In our guts, bacteria create some of the same chemicals that our brain neurons use to communicate with one another, such as dopamine and serotonin. And, the microbes are able to deliver the chemicals to the brain; affecting the eating behavior of our dogs.

Poop eating is natural across the animal kingdom, except for humans.

For example, mice eat the poop of healthy mice, which changes their gut microbiome.

My current dogs, BeeBop and Popeye, Bogart’s great great great grand dogs, don’t eat poop, at least that I know of! My personal experience and stories I hear from many feeders of meat-based diets with vegetables suggest that dog’s eating species appropriate diets – like Darwin’s — eat less poop. We’ll learn more in the future, and your comments will help. Thank you.

1 Ed Yong, I Contain Multitudes. The microbes within us and a grander view of life. (Harper Collins, 2016)

Steve Brown - Pet Nutritionist
Steve Brown is a dog food formulator, researcher, and author on canine nutrition.

Developer of the first AAFCO-compliant raw dog food, and one of the leading low-calorie training treats, Charlee Bear® Dog Treats. He is also the author of two books on canine nutrition (See Spot Live Longer, and Unlocking the Canine Ancestral Diet (Dogwise Publishing, 2010); and a 40-page booklet, See Spot Live Longer the ABC Way. 

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