Help, over the past week I've had 4 of my girls and one of my roosters come down with some sort of respiratory illness. Symptoms include gurgly/raspy breathing, sneezing with no nasal discharge, and bubbly/ swollen eyes. 2 hens have gurgly breathing only and 1 hen and my rooster have 1 swollen eye and no breathing issues. There is no fowl odor coming from their faces so I don't think it is infectious coryza. I'db een dosing with Tylan (1/2 cc) but I increased the dose to 0.75-1cc depending on the size of the chicken/rooster because the symptoms were not going away. We are currently on day 4 for 2 of the girls and day 1 for my buff orpington and my rooster. However the tylan does not seem to be working, could this be some sort of virus??? Are their any other recommendations that you all my have as far as medications or treatments go???? I can't bring myself to cull these birds without trying every viable option. There are no vets in my area that treat poultry.