A dog who eats his own or other animal's stools generally isn't at any health risk, but it's an unpleasant habit, and one you want to discourage. Technically known as coprophagia, eating stools is natural in some settings. Mothers will eat the stool of their newborn puppies to keep the bed clean, and many adult dogs will do the same around younger pups. Stool eating that develops suddenly in dogs, however, may indicate health issues.
Check His Diet
If your dog isn't getting enough of the right kind of nutrients, he may resort to eating stools. Make sure you are feeding him enough, and feed a high-quality food. If you're only feeding him once a day, he may do better with more frequent, smaller meals. Even if he's getting enough food, and the food is high quality, going 24 hours between feedings may send him looking for something to eat between meals.
Check For Internal Parasites
Internal parasites rob your dog of nutrients, so, even if he is eating high-quality food and plenty of it, he will still feel hungry and unsatisfied. Checking for internal parasites will require a trip to the vet, but it's an inexpensive problem to treat. If the stool eating has gone on for a while, however, you may find that your dog continues out of habit. If that happens, supervise your dog's outside time as much as possible to prevent him from eating stools until the habit is broken.
Boredom can cause stool eating in some dogs. If your pup has nothing to do all day but lie in his back yard with little stimulation, he may look for ways to entertain himself. While stool eating may not sound like much fun, dogs explore the world with their mouths. Try adding short bursts of exercise or play in your dog's day to prevent boredom. A quick game of fetch before work, a walk when you get home and a grooming session before bed add some variety to his day.
Clean It Up
Cleaning up your dog's waste on a regular basis is probably the easiest way to prevent and stop stool eating. Even dogs that do not typically eat stools may develop the habit to keep their yard clean. The best way to prevent your dog from eating stools is to go outside with him and clean up the waste while you're out. If that isn't feasible, try to make a daily or every other day sweep of the area.