Why Do Dogs Eat Poop?

coprophagia in dogs

Story at-a-glance -

  • UC Davis researchers published a study recently of coprophagia (stool eating) in dogs
  • Some of their findings: coprophagic dogs tend to be greedy eaters, live in multi-dog households and prefer fresh poop under two days old
  • The researchers also found that neither commercial deterrent products nor behavior modification training are effective in curbing poop eating behavior
  • In my experience, there are both dietary and behavioral reasons for poop eating in many dogs
  • The most effective way to prevent coprophagia is to feed a nutritionally balanced, human-grade diet with appropriate supplementation, and be sure to pick up your dog’s poop immediately to remove the temptation

By Dr. Karen Shaw Becker

It's time for another discussion of every dog parent's favorite subject — poop eating! The scientific name for this seriously disgusting habit is coprophagia, and it's quite common among dogs. Cats do it occasionally, too, but not nearly as often as their canine counterparts.

The behavior is so common in dogs, in fact, that a team of researchers from the Center for Companion Animal Health at the University of California, Davis, decided to see if they could determine the factors involved in stool eating. They also evaluated several products claiming to treat the issue, along with some behavior modification techniques.1

The title of their published study, "The paradox of canine conspecific coprophagy," means the researchers looked specifically at poop eating behavior in which dogs eat dog poop (their own or another dog's). The word "paradox" suggests, and rightfully so, that since dogs are known to be averse to poop (thus our ability to housetrain them, and the effectiveness of crating when housetraining), the fact that some dogs eat the stuff seems contradictory.

UC Davis Coprophagia Study Used Two Large Web-Based Surveys

For their study, the researchers used two web-based surveys. One survey, which received 1,552 responses, found that 16 percent of the general dog population could be categorized as poop eaters based on having been caught sampling the goods at least six times.

Of this group, 76 percent had been caught in the act more than 10 times. There were very few similarities among the dogs — not their diets, their age at weaning or their current age. Their owners reported that all were easily housetrained, which suggests they possess a normal canine aversion to feces.

The other survey was geared to owners of known poop eaters and garnered 1,475 responses. The researchers found that 62 percent of these dogs indulged their stool eating habit daily, and 38 percent weekly. Some additional findings from the study regarding coprophagic dogs:

They were more likely to be greedy eaters than non‐coprophagic dogs

They frequently lived in multi-dog households, which might suggest there's a social or "follow-the-leader" component to the behavior

75 percent were older than 4 years of age

They also tended to eat dirt and cat poop

Many belonged to the terrier or hound breed groups; the most likely individual breed was the Shetland Sheepdog and the least likely was the Poodle

85 percent preferred fresh stool (not more than two days old)

Verdict on Commercial Deterrents and Behavior Modification: Don't Bother

The UC Davis researchers also used the web-based surveys to assess the effectiveness of 11 commercially available products that claim to help curb the habit, including 21st Century Deterrence®, CoproBan®, Deter®, Dis‐Taste®, For‐Bid®, Nasty Habit®, NaturVet Deterrent®, Potty Mouth®, S.E.P®, Stop Stool Eating® and Stop Tablets®.

According to survey respondents, just one of the products scored a meager 2 percent for effectiveness. Three others had a 1 percent success rate, and the rest were a complete bust. Behavior management to curb poop eating was also ineffective according to survey answers. The "leave it" command scored the highest rate of just 4 percent.

Generally speaking, most experts agree coprophagia is a normal dog behavior that ranges from difficult to impossible to extinguish. The best way to prevent a poop eater from doing his thing to ensure there's none of his poop left behind to sample, and when out for walks, he should be carefully supervised in case another dog or animal has left a "deposit" nearby.

Do Dogs Eat Poop to Correct Digestive Deficiencies?

In my experience, many dogs start eating poop because their bodies are prodding them to correct an insufficiency or imbalance in the digestive process. Perhaps the pancreas isn't producing enough insulin or other enzymes, for example, or maybe the balance of good-to-bad gut bacteria is out of whack.

Dogs eat poop not because they think it's yummy, but because their bodies are urging them to ingest something present in the feces — something that may be missing from their diet.

It's been my observation that coprophagia is more prevalent in dogs fed kibble, which is a biologically inappropriate diet that can create a chronic digestive enzyme deficiency. Since the feces of other animals are a good source of digestive enzymes, dogs with a deficiency will sometimes ingest enzyme-rich poop.

In fact, rabbit poop is a very rich source of not only enzymes, but also B vitamins, which is why many dogs, given the opportunity, will happily scarf up rabbit droppings. I think the reason most poop eating dogs limit themselves to fresh feces is because in addition to digestive enzymes, it also contains the high levels of microbes necessary to regenerate beneficial bacteria in the gut.

Behavioral Causes of Coprophagia in Dogs

Some dogs, especially those in kennel situations, may eat poop because they're feeling anxious or stressed. Research also suggests dogs who are punished for inappropriate elimination can convince themselves pooping itself is bad, so they hide the evidence by eating it.

Coprophagia is also a problem in puppy mill dogs. Puppies who go hungry, are weaned too soon, have to fight with others for food or are forced to sit for weeks in a small crate with no physical or mental stimulation, are at high risk of becoming habitual stool eaters. Coprophagia can also be a learned behavior. Older dogs can actually role model poop eating behavior for younger dogs in the household.

Some dogs are feces connoisseurs who are quite selective about the poop they eat. Some favor only poopsicles (frozen poop); others will eat only the feces of a particular animal, and some dogs only indulge their habit at certain times of the year!

5 Suggestions to Help Curb Your Dog's Nasty Habit

  1. Feed a nutritionally balanced diet containing human-grade (preferably unprocessed) protein, and supplement with probiotics and digestive enzymes to help curb your dog's urge to find less appetizing sources of free enzymes around the yard or in the litterbox. I've also had success using Homeostatic Soil Organisms as a source of probiotics.
  2. Pick up your dog's feces immediately, as soon after she eliminates as possible.
  3. If your dog favors litterbox snacks, place the box in a location in your home where she can't get to it, or consider purchasing or making a dog-resistant litter box. I also recommend you improve your kitty's diet, and add digestive enzymes and probiotics at meal time to make your cat's poop less attractive to your dog.
  4. Make sure your dog has toys that stimulate her brain and alleviate boredom. Also ensure she's well-exercised. Bored, sedentary dogs tend to develop far stranger behaviors and habits than dogs who get plenty of exercise and mental stimulation.
  5. If you want to experiment with some over-the-counter coprophagia deterrent products, make sure you look for a nontoxic product that doesn't contain MSG.

If despite your best efforts your dog's poop eating behavior isn't improving, or is getting worse, I recommend making an appointment with your veterinarian to rule out any underlying medical reason for the behavior. Interestingly, microbiome restorative therapy can be very successful for pet parents who have tried everything to curb this gross habit.