I have had chickens all my life, but have never had any of them get sick. It started with one and has spread to most of the others before I could do much to resolve the issue. They are sneezing, have mucus coming out from their nose holes, and seem to make a wheezy rattling sound when they are still and sleeping. The first one that got sick seems to be mostly better and one rooster who had a swollen face from it seems to be feeling better today. The other rooster, who was fine yesterday, really seems to be taking it hard today. The other ones didn't seem to be slowed down too much by it, though I could tell they didn't feel good. They still ate and drank just fine and run around the yard. This guy didn't even want to come out of the coop. I inspected his mouth and he has very thick mucus in there and is breathing primarily through his mouth. I was wondering if there was anything I could give him, like benedryl, to make him more comfortable. I think it is probably a virus, since the other chickens appear to be recovering from it. He's a Cuckoo Maran if that makes any difference? Any Suggestions?