Start him on Duramycin, It is for cronic respitory colds.
If you are going to buy this tomorow morning is best, what you do is
take away his water tonight.
and mix in the duramycin in his water then give it back to him. ( 2 teaspoons per gallon) but only make qrts at a time becouse it is only for him, But you should all the birds you have, they could have the respitory cold and show sighns yet.
if you treat more than that one then make it by the gallon, you use this portion within 8 hours, then need to make new mixture.
the treatment goes for 7 to 14 days.
Also buy some vetrx, and warm up the bottle in a cup of water, put some on his beak , on his nostrils, wattles and comb,
and under his wings, and even sprinkle a little bit in his bedding.