Today I noticed that one of my GLW hens was sitting down at the end of the coop, kind of 'scrunched-up' like she wasn't feeling well. It didn't take me long to catch her(Very unusual) and i could see right away her comb was real pale and when i felt her chest i discovered an empty crop as well. She is still poo'ing but it's BRIGHT yellow. She is GLW, 8 months old & been laying for close to two months now. I recently treated the entire flock with Ivomec pour-on to take care of a mite/lice problem. food is Nutrena(i think) All Flock & has been forever. No idea what's going on with her because the rest of the flock is just fine. I have seperated her into an empty brooder space with food & water but don't know how/if i should treat her? Here's the pictures. yellow poo on her rear it's kind of watery/slimy almost seperated and not complaining about it... normally she'd be screaming for the roo.