One of my ducks has not been acting well lately and we have brought her in and have been treating her with antibiotic. She's just been acting very depressed and lethargic and has been isolating herself from the flock. This duck has an issue with weak legs ever since she was a duckling and as you all suggested, we have started her on Niacin. Tonight, we decided maybe a warm bath would help her feel better. We noticed for the first time that she is holding one of her wings down lower than the other one. When I felt the top of it, there is a knot there. Does it look broken to you all? If so, what do I do for it?