My 3 y/o hen has one eye closed (no injury noted)and is lethargic. She is in her nest most of the afternoon and not much interested in feed. I'm not sure what to do for her and thought maybe an antibiotic was in order. Is this something I can buy at a feed store, what kind? I'm bringing her into the garage where I have an enclosure that will make it easier to care for her. It is not cold here, about 80 day and 50's at night, so there isn't much worry that she will be cold in there alone. Thanks for any advice, amy