Went out this morning to give them their warm oatmeal and noticed my Brown leghorn has a slight gurgle when she breathes and has a cough. New at this but sounds respiratory. Her comb and wattle are red, eyes are clear, nose is clear. I don't know about her droppings, I have 10 chickens but looked around their yard and haven't seen any unusual looking droppings. She is slightly puffed and definately not her active self. She hasn't layed in 2 days. She lays every other day and should of layed yesterday. Should I seperate her now? No one seems to be bothering her. All the others seem fine so far. The only antibiotic I have is Duramycin-10. If I need to give this to her how much. I have a 3 gal or a 1 gal waterer. Please...my poor girl is sick. I need any advise. Ive looked through my Chicken Health Handbook but it's like looking for a needle in a hay stack.