My Woosta is staggering

[Fanny's Mom]

He recently was showing signs of a respiratory problem. He's a very mean bird (but I love him anyway) and after chasing me to the door of the run, he was breathing very hard and I could hear his lungs were congested. That was a few days ago and since then I've tested his lungs and I thought all was was because he was chasing me no problem. But today when I let him out of the coop, he could hardly walk. . .staggering like an old drunk. He improved a little after trying to walk for a while but when I left him his was still squatting down to relax every couple of feet and not at all interested in chasing me. He's crowing to beat the band as he always does and shows no signs of illness in his eyes. He seems alert; he just can't walk. Is this the end for my old bird or is there something I can do?