So we've had some Tylan 50 on hand for a week now, because some sort of respiratory illness has been working it's way through our flock for a bit. We had decided to not medicate unless it went further than some rattling and sneezing, which is exactly what it's been doing for the other birds infected. Our Brahma was the latest to get sick, and the first to show any other symptom. Pearl (our Brahma) was eating and drinking fine today, but when we let her out of the run around noon, my wife noticed one of her eyes were foamy and the side of her face was somewhat inflamed (please see pic below). She was told and proceeded to dose her with 1cc of Tylan 50, and to do so every other day for 3 or 4 doses. Is this correct? Also, does this symptom point to any specific illness?