Update - HE LIVES! I tried aspirating and got some air out but it just kept collecting there again. He was so sickly and I really thought he would die. I gave him some metronidazole as I had seen it recommended in another forum, cayenne in his water, and kept him separated for a few days from the flock. He is back to himself completely, eating well, running up for treats, strutting and flying up high to perch again. Phew! The swelling is still there but I'm confident that it'll go as it's less every day. Thanks for all the help.
