My RIR rooster, Big Red, is about 18 months old. Just today, I notice he is rattling when he breathes. He looks great, none of his 20 girls are doing it, and if I was a little deaf I wouldn't know anything was wrong. But today he has quite a rattle--sounds almost like he is snoring. He must have congestion. Anyone have any suggestions on what to do for him? We have had some cold weather--been down to 15 or 20F a couple nights, but they have a nice, draft free chickenhouse, 11ft by 12ft, with 20 chickens in it. They get warm water every morning, as I have had to break the ice on their water now that it is freezing. It warms up during the day. Suggestions??