I have a flock of several breeds of chickens, BO's, BA's, SLW, CW, NH, Cornish, Rocks, Brahmas, and Cochins all are standard size, 26 total. It has been very cold here, subzero at night and dailey high's of only 5-15. They have a coop lined with pine chips and straw, a small heat lamp. About half of my flock has a cough or sneeze there is no discharge. They are all eating and drinking fine. Egg production has pretty much come to a halt! I am only getting about 2-5 per week. (24 are hens) I was getting 10-18 per day last fall befor the weather turned. I am not sure what to medicate them with or if I should let it run it's coarse??... Any suggestions????????????