I have a dozen cornish cross chicks and a few have started coughing or sneezing, I can't tell which is which. There is no mucous evident and all are eating and drinking well. No bloody or odd stools either. These guys are over a month out from their butcher date so I'm comfortable giving antibiotics. Also, they were vaccinated for Cocci by the hatchery. Ideas? They're in our garage with a heat lamp (75 temp in hutch)but the weather here in OK has been wet and fluctuating.