Why Do Dogs Eat Their Own Poop?


In humans, it’s considered a sign of deviance and insanity. In dogs, there’s nothing more natural. We’re talking about eating poop. The practice is known as coprophagia, from the Greek ‘copros,’ for excrement, and ‘phagia,’ referring to consumption. It’s a pressing question for plenty of shocked and horrified dog owners: why does my dog eat poop?

According to a recent study on the subject, an unappetizing 16 percent of dogs eat feces frequently. The author, Dr. Ben Hart of the UC Davis School of Veterinary Medicine, presented his research at the 2012 Veterinary Behavior Symposium.

As part of the study, Hart found that coprophagic behavior is highly pack-related. In fact, the more dogs you have, the more likely they are to eat poop, especially those playing a submissive role. Dogs are famously attracted to the infections, excrement and discharges of others in their pack. Indeed, eating other dogs’ poop is more common than eating one’s own, says Dr. Hart.

Perhaps surprisingly, in the vast majority of cases, the practice prevails regardless of the dog’s diet. Additionally, the study found, neutered and spayed dogs are more likely to eat poop, and some breeds have a greater disposition to do so, too — border collies, shelties and German shepherds, for example.

When Is It Normal?

Is canine coprophagia as unnatural as it seems? Unfortunately for germaphobes and polite company, dogs’ poop-eating behavior is not just common, but entirely normal in most situations. People used to think dogs indulged in savory stools due to poor diet or failing health, but this theory has been debunked.

Why do dogs eat poop? Most dogs repurpose fecal matter simply because they learned to. Coprophagia is commonly behavioral in nature. It is, for instance, frequently observed in puppies. Momma dogs clean up their pups’ poo by eating it. Some young dogs are mimicking this practice; most will grow out of the behavior as they get older.

Biologically speaking, coprophagia is simply nutrient recycling. Animal digestion is never 100 percent efficient, so feces inevitably contains the nutrients that didn’t get metabolized before passing out of the body. To a dog, poop is viable, second-round food, albeit not as rich as the first round. Just because humans don’t see the gastronomic value of poop doesn’t mean the same is true for dogs. From a dog’s perspective, feculent morsels may harbor interesting smells, delectable textures, and infinitely varied tastes worth sampling.

When Is It Pathological?

Poop-eating is not ordinarily a sign that anything is physically wrong with the dog. In exceptional cases, however, the behavior can be a secondary sign of an underlying problem, usually involving a nutritional or enzymatic deficiency or some sort of gastrointestinal disturbance.

In such circumstances, veterinarians say, it’s not that the dog is trying to supplement its diet, so much as his poop tastes especially good. Doggie dump is more appealing when it still has much of the nutritional content of the original chow. Thus, in rare cases, unexpected coprophagic behavior could indicate that Fido’s kibble has been poorly digested. When coprophagia represents an underlying medical issue, there will usually be other physiological symptoms, too, such as diarrhea.

Like many normal dog behaviors that persist in an obsessive-compulsive, repetitive or attention-seeking manner, coprophagia can also be a sign of stress and anxiety. Owners who suspect their dogs may be consuming feces for pathological reasons should seek further explanation from a trusted veterinarian.

Evolution of Fecal Consumption

Did dogs evolve to eat poop? Yes, it seems so. Coprophagia is a natural evolutionary behavior that is widely observed in domesticated dogs, wild dogs and wolves. As revolting as it sounds, the consumption of feces is quite a versatile practice that can serve a number of useful purposes.

Although rare in domesticated dogs, wild dogs and canids may eat poop to supplement their nutrition when food is scarce. Emaciated wild dogs and canids have been observed readily lapping up stools, presumably harvesting whatever calories they can find to stay alive. Dogs don’t just eat their own and other dogs’ poop, either. Our canine companions also gulp up other animals’ deposits, especially that of large herbivores like horses, sheep and deer, which tend to deposit feces with the greatest nutritive value.

Wild dogs eat poop to keep their dens clean. It’s also a way to protect yourself and your pack from predators. Leaving smelly piles lying around makes a pack vulnerable to predators on the prowl. Coprophagia is a clever way to avoid detection when it really counts.

Domesticated dogs evolved from decidedly opportunistic scavengers with little of the taste aversions human beings have grown accustomed to. Moreover, dogs have always had stronger guts than humans. That said, coprophagia has its dangers. Eating the stools of wildlife or unfamiliar, unvaccinated dogs in particular can transmit internal parasites and should be actively discouraged.