Some dogs, especially those in kennel situations, may eat feces because they are anxious or stressed. One researcher suggests that dogs who have been punished by their owners for defecating inappropriately start to think any defecation is wrong, so they try to eliminate the evidence.
Another theory is that coprophagy (stool eating) is a trait passed down through the ages. Dogs' cousins, wolves and coyotes, may often eat feces if food is in short supply. Feces from herbivores (plant eaters) contain many vital B vitamins. Some researchers suggest that wolves (and some dogs) may eat feces to replenish their vitamin supply.
Dogs who eat their feces usually do not have a dietary deficiency. Some medical problems, however, can contribute to coprophagy including severe disorders of the pancreas (pancreatic insufficiency) or intestine, severe malnutrition from massive parasitic infestations, or starvation. These cases are rare.
In some instances, coprophagy may be a behavior learned from watching other animals. It may also become a habit in the course of play and puppies having to try out the taste of everything.
Read our helpful article on how you can break your dog of this habit here.