I have 22 chickens that are 12 weeks old, I was outside with them on Saturday evening and noticed a couple of them sneezing loudly. My husband said that he said some boogers on a few of their noses but we didn't think much into it because the wind has been blowing like crazy (+30) so we thought it might have just been dust causing it. Sunday morning we woke up and i noticed one of my girls was breathing with her mouth open and almost everyone was sneezing and sounded like they had a rattle. We got some durmycin 10 to put in their drinking water. Yesterday I noticed a couple of my chickens were laying around not eating or drinking much but the rest of them sounded a ton better but there was a lot more of the mucus on the noses and sounds like sniffles. my husbands fav rooster had bubbles coming out of his nose. Last night the rattling was gone from almost everyone and only a few sneezes. This morning everyone is up and eating. Made them some egg yolks and no one turned them down. Not one sneeze. Not one rattle. However, there in one who has goop in her eye. So my question is what am i really looking at? I thought things were getting better but the one with the stuff in her eye concerns me. And what causes this? We clean their coop once a week. I clean the feeders and waterers everytime we refil them. Yes I did add new chickens to the flock without the quarantine. They were my mother's day gift. I made sure to ask lots of questions and the place was clean. And they are the only ones not showing any symptoms at all. This is our first time with chickens and this has just really discouraged me from doing it again. We lost 2 at days old for no reason, my favorite chicken turned out to be a rooster, and now this... I was certain we were doing everything right. Oh and lastly, none of them have any kind of foul smell.