Dogs can be so gross sometimes can't they?
There's something you can buy at a pet store to stop that, one brand I know of is called DisTaste (there are others though). It's a powder you put in the dog's food and it makes the poop taste really bad to them (how it possibly tastes good in the first place I don't know
). I've given it to my cats to stop my dogs from "snacking" out of the litter box - worked like a charm by the second day
. You usually only have to use it a few days and they get the picture pretty fast. You may have to repeat every once in a while if you notice the habbit coming back, depends on how determined your dog is though
. If it's only the other dog's poo he'll eat, feed it to the other dog.