I need help diagnosing my WH duck's foot. This started out as a small limp earlier in the month but has morphed into a completely twisted foot and swollen joint. It looks like something that would be described as a vitamin deficient in a duckling, but this is a grown duck who should be getting all the nourishment she needs. It doesn't seem to be a broken bone or an infection either. I currently have her isolated from the others, and am adding nutritional yeast to her feed just in case.