I have noticed a few of my chickens sneezing, one sounds congested when it's breathing, and another one we had to cull because its eyes started swelling shut and it looked awful. I like to help the chickens as much as possible but if they get that sick, I'd rather go ahead and get rid of them then risk the others getting that sick as well. I prefer to take the natural method when preventing illness, I put apple cider vinegar in their waterers to try and help. But i'm wanting advice from other people about what they use to treat/prevent respiratory issues with their chickens? I need some ideas on what else I can do. Any information is greatly appreciated. Thank you!!