My one and a half year old black star, sex linked hen stopped moving her right wing 2 weeks ago. I took her to the vet and he found no marks. Then a few days later she started limping. I have kept her in, but she isn't getting better. What should I do? She lives with 2 other hens, 2 bantoms, and 5 ducks that go out all day, in a 10 x 12 coop, with 2 small coops inside for the hens.