I have a 12-week-old American Gamefowl cockerel who has one eye closed and his acting lethargic. His face also looks a little swollen. He is part of a closed flock, which makes me wonder if it's something other than coryza. He is egg hatched and his parents both seem fine. Also, he has no nasal discharge, no respiratory difficulty, and no smell. The symptoms began the day before yesterday, and I see no signs of diarrhea or bloody stool. He will eat a little, but has very little energy and low appetite. Anyone with any help would be greatly appreciated!!