I have one silkie that is coughing (no wheezing) and has bubbles in her eyes. Then I have a buff who is getting very skinny she's not as perky as the rest, she eats but much rather stay in the coop under the heat lamp all day. I have seen a bit of runny poop and some BLACK poop in the coop. Does this sound like Coryza? What can I get to treat the whole flock? I think I have caught this pretty early on. I don't see any of the rest sick at all. Is there an over the counter antibotic I could put in there water just to see if maybe its just a cold? I haven't added any new chickens, this flock has 6 2 year old hens one which is the sick buff and the rest including the silkie are a year old. Is there anything over the counter antibotic that i could add to the water? Maybe its just a cold? we did have some terrible negative weather all last week (this is when I noticed my buff getting sickly and very skinny ) the silkies bubbles showed up yesterday... Help please! I don't want to end up losing them all!