Buddy is a labrador, and he has this strange tendency when excited. We've had him checked for anything wrong with his back legs and he's fine, which is why this isn't in the health forums. He can walk (and run) fine, but when he gets reaaally excited he'll run like a rabbit or a hare, tucking his back legs in.
It makes him go faster, so is that it? Does he like going super fast? Also, if we tell him to get in to bed and stop he'll get in to bed and turn around a few time as if he's trying to tire himself out or something.
What in the name of the Lord is he doing?