Do you see any other signs, such as:
Symptoms include listlessness, weight loss due to decreased appetite, swollen or bloated body, gaping, open mouth breathing, often with audible exhalations when in an advanced state. Wheezing may be heard, or clicking noises when breathing. Bubbly, stringy or sheeting mucous appears in the mouth. The head may be held in a raised position to facilitate breathing. In snakes, the tines of the forked tongue may be stuck together. Respiratory infections in snakes are especially dangerous in those snakes who have only one functioning lung (colubrids, etc.).
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(source: http://www.anapsid.org/rti.html)
You should probably take your animal to the vet if you think it has an RI.