Why is my Malagasy Giant Hognosed snake wheezing?

My malagasy giant hognosed snake is 2 1/2 years old and has been very healthy. She has always excepted pre-killed and frozen mice willingly and has shed frequently. The past two feedings she hasn't ate. I haven't changed anything about her environment/heating/lighting. I have also noticed that she has been wheezing for about 2 months. I originally thought she was hissing, but I think now after further research that she is wheezing. I changed her bedding in hopes that maybe it was the problem. Also, her nose is very dry looking like she needs to shed and it has been that way for a month now. If anyone could offer any advice I would greatly appreciate it. I have a feeling this is going to end in a large amount of vet bills.