How old is he?
Has he been checked for parasites?
Was he vaccinated for Marek's Disease?
What do his stools look like?
Is he eating and drinking?
Where is he being kept, could it be too hot or too confined?
Can you post a picture of him. When you say panting - do you mean open mouth breathing? Are his wings extended/hanging down and away from body? Is he laying down or standing in one spot? What color is his comb? Have you felt his crop for impaction?