I need help from all you experts deciphering the info on this site about respiratory illnesses. First here is my issue: I introduced 2 new birds to my 2 remaining birds and one of them sneezes every now and then and makes audible noise when breathing only sometimes. I have had them for 3 weeks. I have not treated any of my birds and have not quarantined. Could this just be how this chicken sounds and acts? Here are my questions: 1 From what I have read, it seems like the bird will be a carrier and even if I quarantined when I first noticed the rest of the flock would have been exposed anyway. Is that true? 2 it seems like most respiratory illnesses are severe and would be accompanied by other symptoms and would have progressed in 3 weeks to something more. Is that true? 3 should I give antibiotics if there doesn't seem like any secondary bacterial infection is going on as of yet or should I wait for true , consistent wheezing, bubbly eyes, snotty nose/head shaking, lethargy? I am hesitant to give antibiotics in the water to all and lose the eggs from my 2 girls (the only ones laying at this point). 4 once they get this do they have it off and on or is it like us when we get a cold in that it goes away and that's it (other than I know chickens shed the virus and can infect others that have not had the illness)? 5How long do these things take to run their course within the bird and how long is the incubation for the other birds to show symptoms? My friend that gave them to me kept them both together and the other bird he gave me does not have any symptoms nor are my original 2 showing signs yet. Thank you so so much for any help you can provide!