Can you tempt him with some treats, like finely mashed boiled egg yolk., plain,vanilla yogurt- anything you can get him to eat is better than nothing. You could try getting Polyvisol infant drops and giving him 3 drops, 3 or 4 times a time. Just put the drops at the front inside of his beak. So if he doesn't want to swallow he can push them back out.
Sometimes being brought into the house with some heat from a lamp will make sick birds feel better, especially being away from the stress of the flock. You could give him a stuff animal to cuddle with.
Sometimes being brought into the house with some heat from a lamp will make sick birds feel better, especially being away from the stress of the flock. You could give him a stuff animal to cuddle with.