It’s one of the nastier habits your dog may develop, but poop eating, or coprophagia to give it its proper name, isn’t necessarily the risky and unhealthy trait owners often imagine. The consumption of feces, whether the dog's own or belonging to another animal, is quite normal, especially in puppies and nursing mothers. In fact, dogs are usually, but not always, capable of eating feces without getting sick.
One of the dog’s most powerful instincts is to keep the nest area clean. So if necessary, a nursing mother will gobble up the poop of her puppies in order to keep harmful bacteria from spreading and to stop the nest from getting smelly. In keeping the nest from getting smelly, she is acting on her instinct to reduce the chances of her young’s scent being discovered by a potential predator, something that wild dogs do for survival. Because of these instincts, nature has blessed your dog with a robust gut that enables her to eat substances that would make a human sick.
Although dog owners may wince at the thought of eating it, not all poop is foul-smelling and sloppy. The manure of herbivores, such as horses and cows, while not a culinary delight, is relatively easy for dogs to eat. This is because it contains mainly vegetation, and due to the size of the average horse or cow dropping, some dogs are quite happy to dig in and eat around the fully digested matter and pick out the vegetation that traveled through the animal partially digested.
Although the most likely causes of coprophagia are linked to the instinct for keeping the nest clean and tidy, some dogs actually eat poop because they want to. This is especially true of dogs with nutritional deficiencies, such as malabsorption syndrome. Dogs who are not getting sufficient nutrition from the food that they eat supplement their intake by feasting on the feces of other animals.
Dogs can't move their jaws sideways, meaning they chew differently to humans. They tend to gobble up their food quickly. Another crucial difference between dogs and humans is that dogs produce no digestive enzymes in their saliva. This means that when a dog eats, he strives to get whatever he is eating from mouth to stomach as quickly as possible. If a person were to eat poop, it would spend longer in his mouth before he could swallow and he'd be more inclined to spit it out. Dogs don't eat in this way, so they are more capable of tolerating foul tastes and smells than people are.
Tolerance of Bacteria
Dogs have evolved to eat raw and decaying flesh. The canine stomach produces a high volume of hydrochloric acid, enabling it to safely process the abundant dangerous bacteria without causing illness. This tolerance of bacteria enables dogs to digest feces without becoming ill. However, this doesn't mean that dogs are immune from health problems. Their taste for raw meat and feces means they are much more prone to ingesting parasites, such as worms. Furthermore, dogs with weakened immune systems may exhibit a lower tolerance digesting feces.