My 1 year old leghorn has been acting different for almost a week. She is lethargic but still walking around slowly. I tried soaking her to see if she is egg bound but nothing happened. She is pooping small amounts of light yellow runny poop. I'm trying to treat her with corid but she hasn't been drinking much at all lately. Shes been eating small amounts of the feed and some seeds. I have 8 other chickens and they all are fine. What could be wrong?? Picture attached