Chicken butt injury

[o-townchicken]

Hello, SO, this is my poor chicken's butt. She often has poop masses stuck below her butt that we clean frequently. SHe also feather picks. The other chickens don't pick on her. We seperated her and put mosquito netting around her enclosure, the flys were swarming her. I am abot to go to the feed store(2hours away) to see if they have any antibiotics. Does anyone have any suggestions, comments or advice. We need some bad! Btw, she is eating and drinking
thanks

 

[Beaky Buzzard]

Put neosporin without pain killer in it on her.Thats really all i know to tell you....