Today I decided to take my King snake out. He's a 4 foot sub-adult male, and I've had him for almost 2 years now. So I took him out, held him, let him run around my floor a little and that's when he started to sneeze. He sneezed a good 3-4 times. I thought it was kind of odd, since I never see him do that. Then, when it was silent in the room and I was listening closely for anything else, I heard tiny little popping noises when he exhales. Right then I thought, "Ohh dear god no.." So I went downstairs, got a Q-tip, and brought my brother to my room. I told him I need help (since my King HATES getting his mouth checked and he always jerks back). So we went back to my room and as I secured the head he secured the neck and body. It took me a good 30 seconds to get his mouth open.. like I said.. he HATES getting his mouth checked. When I opened the mouth I was trying to look for some bubbles (found a few in the throat) but what REALLY caught my eye was these brown spots and thick lines on his breathing tube (I forgot what it's called.. so that's the best I could say) and a little on his upper jaw towards the front of his mouth. I also saw on his "breathing tube" some red spots that look swelled a bit so I figured, "Mouth rot? HOW??" I also saw some red and swelling spots on the upper jaw near the brown stuff I saw. Here are his cage conditions:
-Aspen Bedding
-1 half log hide
-1 large water dish
-1 60watt basking bulb

The temperatures are usually between 85-90, but sometimes it hard to tell because the stick-on thermometers SUCK. At night, all of the cages drop as low at 77F. But now I got a red infrared heat bulb so I guess that will help. I think his enclosure gets colder at night, since it's parallel from the air vent.

What are some main causes on how a snake gets mouth rot?? I have no clue if this is mouth rot or not but I NEED to know the main causes on how snakes get mouth rot. I'll post up pictures later because I just bothered him with the whole opening his mouth thing and such so I'm going to let him go for a bit. My camera isn't that good, so sorry if my pictures are really bad but hopefully you guys can help me out