One of my dog has been eating poop. It's a tad annoying but this is surprisingly normal for their ancestors especially when they are protecting their young ones from being tracked by predator.
According to Maggie Rhines of Raw Dog Food System,
When there’s a newborn litter, the mother exhibits poop-eating, possibly because she is wired to clean the den in order to avoid attracting predators – a biological instinct that has been retained by domesticated dogs. Source
More importantly, there's such a thing as the pecking order. In a pack of male dogs, the submissive one eats the poop of the dominant dog.
