respiratory infection? help

[jake00181]

hey everyone, so i've noticed recently that when i'm holding my coastal carpet python i can kind of hear a whistle when it's breathing. However it only happens if it has been out of it's cage for a while. I also opened it's mouth and checked the inside and there doesn't seem to be any bubbles or built up mucus. There also is not anything dripping or coming out of it's nose. Do you guys think this is the start of a respiratory infection? or could it be something not to worry about? if it is a start to an infection, is there any way i could stop it before it gets bad? it also is hard to go to a vet around here, so i'm looking for some answers ASAP. thanks everyone