I have an aprox. 7 month old chicken who I just recently noticed is not acting quite right- she is shaking her head and "yawning" a bunch, and seems unsteady on her feet, and is sitting back on her hocks quite a bit. Her poos are a little loose- her vent area is a little messy- She is eatting ok- she ate the scratch with everyone when I put it out this morning. I am wondering what this might be? and if there is anything I can do for her?