When a dog drags itself across the floor so as to wipe its ass, usually with it's forelegs. May be due to a turd stuck in the butt or general discomfort.
My dog licked his butt so much, he had enough hair in his poop to have a turd hanging off when he came inside. I didn't see it untill he started "butthole surfing" across my new rug. I had to chase him outside and wash that rug. Damn dog.