Unfortunately, many dogs tend to eat poop. They eat their own poop, they eat other dogs' poop, and other animals' poop. Cat poop and horse manure are particular favorites! This is not only gross and unsanitary, it can have health consequences for your dog and you. Your dog can acquire parasites from ingesting other animals' waste, and some parasites can even be passed on to you or family members. Also, medications administered to other animals can be passed in their feces, which can then be ingested by your dog. This medication can result in poisoning and even death if ingested in large enough quantities, so curbing your dog's poop-eating habit is important to prevent the spread of parasites and possible toxins to your dog.
Why do dogs eat poop? Although it is possible they are trying to supplement their diet because it is missing something, or they are having trouble absorbing certain nutrients and are trying to acquire these nutrients from feces, it is also possible, even likely, that poop just tastes good to dogs. Manure from other animals such as livestock may contain undigested substances that your dog finds appealing, and cat feces is high in protein that your dog may find appetizing. It is not uncommon for puppies to experiment with eating poop, as they are testing out pretty much everything to see what they like. This is often outgrown as your puppy gets older. Sometimes dogs that come from abusive situations or were not provided enough food may eat feces due to malnourishment, and having had nothing else to eat in the past. Even when such dogs are provided with a good quality diet, the habit of eating poop may persist.
If your dog is has a feces-eating habit, it is worth taking him to your veterinarian for a complete examination, to ensure he is not suffering from some nutrient deficiency, in which case supplementing their diet may be the easiest way to end poop-eating behavior.
Another method of ending poop eating behavior is to make sure your dog doesn't have access to feces, which means ensuring he does not have access to his own feces, or that of other animals. This will require cleaning up after your dog as soon as he defecates, which is not always convenient, or possible, especially a rural setting.
Therefore, curbing the poop eating habit will involve teaching your dog not to eat their own feces or the feces of other animals. Methods for preventing poop eating behavior include teaching your dog to 'leave it', distracting and providing alternate behaviors, and associating poop eating behavior with negative consequences. Negative consequences are not the same as punishment, which may actually reinforce the behavior if your dog is bored and looking for attention, but associating an immediate negative association with ingesting feces.
To teach the 'leave it' command or alternate behaviors you will need an ample supply of treats. Negative association training may include a foul tasting additive, which can be applied to feces, a loud noise maker, or an electric training collar. If you use an electric collar, be sure to use the minimum setting required to elicit a response, and that you understand how to use the collar effectively and not cause undue stress or injury. You will need to be consistent and ensure your dog does not have access to his own feces or the feces of other animals, except as part of the training regime, during the training period. This will require time and resources to supervise or contain your dog while you break the poop-eating habit.