Though poop is certainly not a staple food for any human, it may come as no surprise that poop is a common part of many a dog’s diet. While a dog eating poop may not be entirely shocking—in fact, an estimated 16 percent of domesticated dogs eat poop—it may still be puzzling. And though dogs can bark and whine, they can’t answer the most important question: Why?
The answer is not entirely simple. Coprophagy, the eating of feces, is practiced by domesticated dogs for several reasons, which may vary with the dog’s age, learned behavior, and environment.
Much of dogs’ dietary variety, like that of humans, stems from curiosity and learned behavior. Like humans, dogs learn from their mothers. Puppies may sniff poop on their mother’s breath and confuse it with their mother’s scent; this could lead them to mistakenly ingest poop. Similarly, dogs that are consistently fed close to poop may confuse their food’s scent with the smell of fecal matter. What’s more, for the first few weeks after puppies are born, their mother may clean them by eating their feces. A still-learning puppy may mirror this behavior despite not having to do it.
As easy as it may be to recognize dogs as our playful and cuddly best friends, we may forget that, before they were domesticated, dogs were wild animals. To reclaim and keep its territory, a wild dog might eat poop that other animals had dropped to mark their own territory. By removing its competitors’ poop, the dog could eliminate other claims to its territory.
Even though today’s domesticated dogs are not exactly scrounging for territory, their ancestors’ need to preserve a domain may have been passed down, evolving into some of the reasons that dogs eat poop today. Dogs may now eat poop for a different functional purpose: to get nutrition. The tasks demanded of dogs—from running to hunting to guarding—require a hearty diet, and dogs’ normal food may not provide all the nutrients they need.
Alternatively, a dog’s coprophagy may indicate stress or anxiety in its life. During housebreaking, the use of harsh punishment to discourage a dog from pooping in an inappropriate place may send the dog the message that pooping itself is shameful and so, to prevent further punishment, the dog may eat its poop to hide the supposed crime. Sometimes a dog under stress from isolation or overcrowding may resort to eating poop.
In rare cases, a dog’s coprophagy may indicate a health problem. Such behavior in adult dogs may signal the presence of parasites, diabetes, Cushing disease, nutritional or caloric deficiencies, inability to absorb nutrients, thyroid diseases, or drug reactions.
Aside from all this, the reason dogs eat poop may boil down to something as simple as seeking attention. And having considered the several observed and studied scenarios presented here, we can conclude that at least one dog has succeeded in getting attention!