Help Wobbley pullet..

[bobby d]

I have a pullet that has been acting strange for the past week. She's not stable on her feet kinda wobbley and wants to lay down all the time. I picked her up and looked her over and she's lost alot of weight but she is eating. There are no other signs of parasites, injury or worms. Can anyone help me? I'm not sure what this could be. Everyone in the run with her are all just fine.