I just brought home a male pekin duck,he has a swollen hock joint and it extends down his leg. The foot is folded up and he doesn't use it. He walks on the first joint. I was told that he hatched out this way. Plus all his siblings except 1 also were hatched with this. Could it be a niacin problem? It does seem to be sore to the touch. I probably cant fix it. But was hoping for some ideas to maybe make it less painful for him. Maybe take down the swelling a little??