Labored Breathing, but No Other Symptoms

[Natasha95]

I've noticed that my Syrian is breathing weirdly. It's hard to explain, but it's kind of like his body jolts when he breathes, almost like when a person has hiccups. It's been going on for a few weeks. He's been fine otherwise. I mean, I've made some posts about how he's been declining with age, but he's still eating and drinking, he still uses his wheel every night for a few seconds at a time, and he occasionally comes out of his cage and runs around and climbs on things. He doesn't seem to be in pain because he's not hunched over, and he's fine with being picked up. I've done some health checks, and his eyes, nose, and mouth all seem fine. He's not making any noise when he breathes, so I don't know if it's a respiratory problem.

In case you need some background information, he's a little over 22 months old and he's kept in the dining room, which we don't use. His cage is across the room from the heater and the window, so he's not directly in front of any kind of draft (warm or cold), and it's an open concept part of the house, so there are no doors and it's all evenly heated. I also keep his cage on the floor (so he can come and go as he pleases when I open his cage door at night), and the window in the room is small and really high up, so again there's no possibility of a draft hitting him.