Allergy?

[Sarah Conte]

My gerbil, Puck, has developed a raw bloody place under his nose.  At first I thought he might have a bit of a cold and it was just discharge, but it's gotten worse.  When I held him today, he was making a tiny squeaking sound continually.  I don't know if it's the sound that is described as clicking or not.  My other two are in relatively good health, so I'm thinking it must be an allergy.  I've been using Carefresh, so I can't imagine what he'd be allergic to.  His energy is pretty good, but when I held him his muscle tone seemed a little lacking. Suggestions? Thanks :) Sarah The Classic Theatrical Struggle: The Show Must Go On vs. This Is Stupid, I'm Going Home!