Andy if he is going faster than a walk he always holds up the back left leg. He has been to his Vet for this and she called it sleepy leg as in he favors that leg for laying. BUT he does this all the time even if he hasn't been laying down. I was going to post this sooner but wanted to record it so you could see what I am talking about. Yes this is a video but I think it was appropriate for this thread
I don't know how to add video's to this, So I hope this works