My young light sussex rooster has acted like he has a cold for the past few weeks. The other chickens in the coop are completely fine, and even he is eating and foraging and moving around fine. His bum is not bloody and neither is his poop. However, his lungs aren't sounding any better, and may even sound a bit worse. He has mucus discharge from his nose, and has to breathe in through his mouth because he cant get in enough air. When I listen it sounds like liquid is in his lungs. Any suggestions or advice would be greatly appreciated!!!