A few of my hens & 2 roosters are showing a little clear nasal discharge & sniffling. I am treating with Terra-Vet 10, a tetracycline hydrochloride soluble powder, because that is the only thing I have for a respiratory style infection. I called my vet & am waiting for him to get back to me, but I thought I would reach out on here and see if anyone has any ideas. They are showing no signs of lethargy, they are eating & drinking fine, they just have a clear nasal discharge coming from their nose/beak, and a hen is sniffling a bit. I live in Central Fl, the weather is in the 60's-70's during day & 40's at night. They have a well ventilated coop they sleep in at night & I treat them for mites & such. Any thoughts?