Technically called coprophagia, the act of eating feces is relatively common in dogs. The reasons behind why some dogs eat feces are not entirely known, but there are a few theories:
Natural Behavior: Mother dogs instinctively lick their pups clean, ingesting their feces. This is a normal behavior that keeps the pups and their environment clean.
Hunger and Food Obsession: A dog suffering from starvation or severe malnutrition might eat anything it can find. Some dogs, though well-nourished, are hungry all the time (this may be a sign of illness or simply the personality of the dog).
Illness: Certain diseases and illnesses can cause a dog to eat feces. A symptom of some diseases is increased appetite or ingestion of inappropriate items.
Anxiety, Fear and Stress: A dog under a great deal of stress may eat his own stool. This may be a kind of self-soothing mechanism in some cases
What are the risks of dogs eating feces?
If a dog eats his own stool, it poses little danger to that dog. However, bacteria and parasites from that stool can technically be transmitted to humans and other animals though contact with that dog's mouth and saliva. If you are unable to keep your dog from eating feces, be sure to wash your hands thoroughly if you are in contact with your dog's mouth/saliva.
When a dog eats the feces of another animal (especially another dog or a cat), he is at risk for ingesting the eggs of intestinal parasites and potentially harmful bacteria that can easily lead to illness. A dog that is known to eat the feces of other animals should have frequent fecal analysis by your veterinarian.
How can I stop my dog from eating feces?
Once you have ruled out medical problems as a cause for the coprophagia, you are left with addressing the behavior. Because coprophagia is generally a self-rewarding behavior, it is difficult to stop. First and foremost, make sure your yard is kept free of animal waste, and pick up your dog's stool as soon as possible after defecation. For dogs that try to eat their own feces during or immediately after defecation, you must be on high alert. Keep your dog on the leash when defecating. If his attention goes to the feces, immediately turn his attention to you (try teaching the "look" command). Reward him for paying attention to you, then immediately pick up the feces and discard it. Another helpful command at this time is "leave it."
Another method to prevent coprophagia is to add something to you dog's diet that makes the stool unpalatable. These products will not work for all dogs, but it will not harm your dog to try (as long as your dog is not allergic to any to the ingredients). Be sure to choose a product that is labeled for dogs, such as "For-Bid" or "Deter."