5 yr old blood python labored breathing

Question
Hi,
Wondered what I can do for my blood python, and if his breathing is cause for concern?  He is 5 yo, 5 ft long, his breathing is loud/labored, a little quicker than usual, and sounds labored like he has shed stuck in his nostrils or has a respiratory problem.  It has been a few weeks since he last shed, and there was no problem with it...he shed completely.  The only other thing out of the ordinary is that he hasn't started eating yet.  He normally takes winters off (we have an undertank heater and a heat lamp for him...it's nice and warm for him, so that isn't the problem) then starts back up again when it gets nice outside.  I mist the inside of the tank to keep it humidified, he has a hide, and he has a pool (I change the water weekly for him).  The substrate is paper towel...changed weekly as well.  I have never had a problem with him, when he starts eating he eats a large rat every 7-10 days.  His name is Link.

Answer
I'd change the substrate and increase the humidity.  I can tell the humidity isn't high enough because you're only changing the paper towels once/week.  If the humidity and temps were high enough they'd be rotten and moldy by then.  Go with either a cypress mulch or spagnum moss and get it wet!  85 degrees/85% humidity.  Give that 3 days to work and if he's still having trouble seek veterinary help.