Coprophagia - a fancy way of saying “poop eating” - is unfortunately common and normal among an estimated fifth of all dogs, no matter how disgusting we find it. It is commonly attributed to:
- Carbohydrate intake
- Vitamin B deficiency
- Insufficient digestive enzymes
- Genetic predisposition/instinct
- Time of year
- Learned behavior
If this all sounds vague to you, that’s because science has yet to pinpoint an exact cause for what is probably the least attractive canine behavior.
Coprophagia alone does not indicate any health issues. In very severe, rare cases, dogs may engage in it as a symptom of a larger illness, but these are unlikely to be seen in most pet households.
Many theories about coprophagia revolve around low-fiber diets or vitamin deficiencies, but they are not substantiated by any data or research. High carbohydrate diets, insufficient vitamin B1, food with below average digestibility are associated with coprophagia, but when studied, did not initiate or intensify poop eating among dogs.
Supplements intended to deter coprophagia often contain thiamine and other digestive enzymes, as well as ingredients that allege to make feces less appetizing for consumption. Questionnaire-based studies have indicated minimal success at preventing coprophagia.
Another commonly held belief is that dogs eat their own poop to regain lost nutrients, much like how some humans take multivitamins. However, canine feces are not considered a rich source of micronutrients. This theory may have its origins in an improperly conducted 1981 study of dogs fed on either a thiamin-enriched diet or its opposite, which later revealed that workers suspected but did not consistently observe coprophagy in all of its test subjects.
In 1966, coprophagy was linked to exocrine pancreatic insufficiency (EPI), a maldigestion disease caused by the lack of pancreatic digestive enzymes. Treatment consists of dietary supplementation. However, coprophagy occurs in healthy dogs who do not have EPI, and even among afflicted dogs, supplements lowered but did not eliminate instances of coprophagy.
Diet changes may or may not affect coprophagia, but the most consistent method of preventing poop eating remains management and preventing access.
Genetics and Evolution
Coprophagia is observed among wolves and wild canids, most likely as a way of keeping dens clean and free of intestinal parasites that would infect puppies. Wolves also consume their puppies’ feces and lick their anuses to keep them clean–a behavior we’ve all observed their domesticated counterparts engaging in!
However, one startling difference emerges between wolves and dogs. While wolves abstain from consuming human feces, dogs will happily help themselves to this nasty treat, suggesting that the consumption of poop has played some role in the domestication and evolution of dogs.
Dogs that eat their own poop are also observed eating the feces of other animals, humans included.
Coprophagia usually shows up between 4 to 10 months of age and starts to decrease after the dog turns 1. While many dogs outgrow the behavior on their own, dog owners must prevent access to poop to try and reduce instances.
Hunger, Confinement, and Learned Behavior
Sex, habits, lifestyle, environment, number of meals, nutritional background, type of food, or diet do not connect coprophagic and non-coprophagic dogs. The biggest predictor appears to be the presence of other coprophagic dogs–namely, if one dog in the household eats poop, the rest will follow.
A study following Antarctic sled dogs revealed that coprophagy is expected among group-kept dogs, lending weight to the theory that poop eating is partially learned.
The biggest commonality between coprophagic dogs is what owners self-describe as “greedy eating.” It has been suggested but never proven that hunger contributes to coprophagia, especially since EPI or other malabsorption issues can lead to increased appetite. Some dogs do stop consuming their own feces when given increased access to food.
However, poop eating can also be an indicator of severe anxiety or stress. House training methods that call for punishing or scolding a dog for inappropriate elimination can teach them to try and hide their waste by consuming it. Punishment is an ineffective method of curbing coprophagia–it’s more likely to have the opposite effect and result in submissive urination.
Some treatment methods call for applying sauces or sprays to make poop unpalatable, but if any poop is missed, you may inadvertently intermittently reward your pet’s gross habit and strengthen it instead.