Breathing out of mouth

Hi y’all, this is my first post on here but I’ve done a lot of stalking through the forums in the past that have helped and I’m hoping to get some help now. About 5 or 6 months ago I got a bearded dragon from an elderly neighbor who was no longer able to take care of him (I’ve had a bearded dragon of my own for the past 10 years and offered to take him in). He’s not really been socialized at all and puffs up whenever I come near or try to handle him. Today I was feeding him and I noticed he was breathing oddly, like puffing out of his mouth. I took a video and I’ll attach it later when I get on a computer. I’m worried that there might be something wrong but I can’t tell if there is or if he was just breathing hard from eating or if he was stressed out because I had taken him out of his tank to feed him.
I would appreciate any insight!! Thanks!

Some of them do that from time to time and it's not necessarily a problem. Does he tend to do this more often after meal time or when you are trying to interact and he doesn't like it? If so, that may be normal. If you see labored breathing and excessive mucous around his nose and mouth it may indicate a problem. If you upload a video to a host like vimeo or youtube I can take a look at it and let you know what I think.