My 9 month old free-ranging BO hen (she was born sort of crooked) but has been fine until this week, so I dont' think it's related to her crookedness defect. this week she started hanging out by herself, and preening her feathers alot and staring at the wall. Yesterday she was drinking an unusual amount of water and appeared to throw up white gunk but still seemed vigorous. Today her feet are kind of curled up (but no injuries) and she just stopped walking. I looked her over but can't find any wounds except that she seems to have 3" long bare patches -- no feathers near the back of her wings on both sides, but no sign of injury that I could tell. The base of the feathers in a few places look kind of caked or balled up with dirt, but that may be normal (she takes lots of dirt baths). Her comb isn't looking healthy tonight. She's very sad looking now. Does she have mites? or a disease? does anyone know what these are symptoms of? Can I do anything for her?