i am haveing the same problem right were the leg begins on the skin its swelled up on spunky i gave vitamins and have ordered brewers yeast for it i thought it was a naicin defciency. either way he just started limping on it before he wouldnt even move i have been letting him swim and that put down the swelling some, idk if it is an injury there is no way for him to get injured is the thing.