Is wheezing/snoring when sleeping a sign of a URI?

I was just sitting at my computer a few minutes ago when I heard a wheezing/snoring sound. I immediately looked around for my cat - she has minor asthma and makes this really funky wheezing/snoring/loud breathing sound when she is very relaxed or sleeping (she's always been like this and vet says there's no need for treatment). However my cat was no where to be found and that's when I discovered the noise was coming from Puff's cage.

Needless to say we will be making a trip to the vet, especially after I picked her up and she huffed spraying me with nose goop (although it was clear, nose hasn't been runny, hasn't been licking, sneezing etc.) but I was just curious if anyone has ever heard these kind of noises before and if they are in fact associated with an Upper Respiratory Infection or other respiratory problems?

Thanks