We have a mixed flock of layers 8 mo old. Have had no problems with them until recently. We had a torrential rainfall a few weeks ago when the hurricane passed by. The henhouse was flooded pretty bad. The chickens stayed soaked for days even thou they had plenty of cover, but rain really doesn't seem to phase them. Here in North Carolina the fall weather changes from 40's to 80's and back again, there's never time to adjust. I've been hearing several hens sneezing, and seen a few wet beaks. I want to treat the whole flock at once. I remember reading somewhere that using Erythromycin (Gallimycin) in combination with Sulfamethazine (generic Sulmet) is a very good treatment for respiratory issues. Does anyone have experience with these in combination? Would I use both drugs at full strength, or a lowered dosage? I have both of these on hand. I live in a remote area with no access to a sympathetic Vet. Anything else would need to be ordered online so that would mean 7 to 10 days before I could start treatment. Any help would certainly be appreciated.