You have 3 adult birds...have any of those ever showed any signs of a respiratory illness?Not really. Him and his "siblings" were integrated with the big girls about a week or two ago, although they don't generally have much contact with each other.
Let me go look.
Nope.
I don't think so...
We have three adult hens, but this seems unlikely. They mostly ignore the littles.
The new birds...you hatched or bought from someone?
How long have you had the new ones?