Well, it is quite common actually. There is the saying of "dogs will never stop eating poop".
Why dogs eat poop?
I have read it somewhere that dogs' digestive systems are depended on a specific mix of enzymes to break down protein, fat, and carbohydrates. They sometimes need to eat poop in order to replenish the special enzymes to help them better digest their food.
Of course, there are other reasons. Some dogs will start eating their own poop when they have parasites, or not getting or absorbing enough nutrients from their regular diet, or when they have issues with their pancreas.
To stop the behavior of dog eating feces, one way to do it is to spray some hot source on their feces. They will not like the taste and they might stop this disgusting behavior after a while.
There are commercial products designed to stop pets eating poop. For-Bid is one of them and proven to be working in many cases but not all.
