Hi,
Just a few questions to help people get a better idea of how to help.
Does his throat look a little "pouchy" or swollen?
Can you hear any sounds when he is breathing in a clam manner - i.e. not being held/ holding himself in an odd position or breathing really fast?
Where is he in the shed cycle?
Can you give us a quick run down of the temps and humidity in his cage lately?
dr del