I have a heavy buff continuously opening his mouth

[Saraillazin]

My heavy buff chick 4 month is continuously opening his mouth & sneezing from 3 days. I gave garlic, hydrallin, peditral but no effects. Plz guide me what i have to do?

 

[Cecisflock]

Could he be hot?

 

[Saraillazin]

Could he be hot?

Today i gave him multi vitamin. But no improvement. She is in much pain.i separated her from flock. I don't know whats the issue.