I have a hen who periodically gets wheezy and has a hoarse laryngitis sounding voice. I give her a little vet rx in water or drizzle some on her beak for about a week or two and it seems to go away, but then returns after a few weeks or a month. This doesn't seem to be related to temperature, bedding, etc. and otherwise she seems normal. I was worried the first few times, because all the info says that chickens don't get colds, respiratory things are serious etc. I always examine her and never see anything caught in her throat. She never has any nasal or eye discharge, and her lungs always sound clear. Any ideas? This has been going on for about 6 months now.