That's just a typical dog Bomber. All dogs eat shit from the litter box although I didn't know this until our Vet told us! We find treats all over the house like Jen said. It's rather disgusting to say the least! Does you dog like to hump the cat?
thats why we have our litter box in a closet with a whole only the cats can go through as they please.. solved the problem we had the same crap going on and it was sickening man.