It's common for dogs to sometimes eat their OWN poop,don't know how common it is for them to eat another dogs poop, I know dogs will eat cat poop
I only had one female that would eat her own if she was not watched, Cody will eat his, so he is carefully supervised. They say to add pineapple to the dogs food to discourage a dog from eating their poop, seems it doesn't smell or taste appealing to them. Seems it works for some dogs, but not for all dogs. Close supervision is the best way to avoid poop eating.