I have 13 hens in a large 8X8 shed. The hens free range during the day. About a week ago, we had a sudden drop in temperature and I noticed some of the hens were sneezing and coughing. Now everyone is sneezing with only occasional coughing. I have looked very closely and see NO discharge. Their eyes are fine. There has been a drop in egg production but the eggs that are being laid are completely normal. The hens seem happy and are still eating well & foraging. We cleaned the coop and replaced all of the bedding in case that was exacerbating the problem. I can't decide if I should treat them with an antibiotic or give them more time to see if their own immune systems can work it out. They get fed organic feed, but I'm not overly concerned with them losing their organic status. I would hate to throw out eggs though while they are being treated. I'd love some input from the BYC community. Has anyone ever experienced this? If so, what did you do?