I have a batch of 15 broiler chicks that started sneezing about three days ago. There is no discharge, no swelling, no gurgling noises, etc everything looks perfectly normal. They have normal looking droppings they eat good, drink good. They are 15 days old today. They've been eating medicated feed for a week (1st week feed store only had non-medicated) A couple of them look like they have labored breathing no gasping just breathing hard (you can see the bottom of their throats move when they breathe) They are indoors, under a light at all times but can get away from it to cool down if necessary. This afternoon I found one bird dead there were no obvious signs of stress. I am really worried about the others and not sure what to do at this point anyone got any ideas whats wrong or what to do?