Dog diarrhea is what they call it when a dog gets the runs.  This can definitely happen, as surely as a person will get diarrhea if they drink too much prune juice or take a box full of laxatives.

Contrary to popular opinion, dog diarrhea is not primarily a health condition.  Yes, there is definitely a health aspect to it, but really, dog diarrhea is a canine way of getting even for all the times they have been neglected at the supper table, all the times they have been held back from getting even with a particuarly lippy squirrel, all the times they have been given a push off the bed in the middle of the night, and all the times they have been forced to stay at home while the rest of the family went to the carnival, lake, or international butcher scraps convention.

All kidding aside, canine diarrhea is something worth checking into with a vet.  If it persists, there is a danger of dehydration.  Plus, whatever caused the diarrhea in the first place (it doesn’t just happen on its own) may need a bit of owner-assisted assistance to help restore Fido to full health.