I'm not sure what s wrong with my 2yr old Barred Rock hen. She has had a thick white drainage coming from her vent for two days now. She is eating and drinking ok but just stands puffed up. I have 49 other hens that are fine. I didn't change food, they have plenty of water.Last week she needed help to get out a large egg, and had another one just behind that one. I have isolated her to stop the rest from picking at her, but I don't know what to do. Anybody have a suggestion?