My poor girl has black goop on her face, and has for a few days. I looked closely and don't see the spots moving but have no idea what else this could be. She has a bald-ish spot on her neck that seems to be filling in. We have three hens that roam around the 1/4 acre yard daily. Someone has diarreah but I can't tell who and wonder if is from all the fallen pears they eat. Egg production is down. Ideas?