My dog develped a bad case of "happy tail" with the tip of the tail becoming raw due to banging it against walls, doors, funtiture, etc. He was a combination pure bred golden retriever (mother) and a black lab fence jumper who got into the mother's yard one day to do the deed.
LOL. Right you are. We lost a vase or two and had drink spilled by the tail! Our also had the habit of bouncing on his front feet when we was excited. He flipped our coffee table over a few times doing this. Our Vet made the comment that he would be the perfect dog if we could remove the springs from his front feet.