Help! Does my guinea pig have URI?

I have 2 guinea pigs. Felix and Cinnamon. Both are not even a year old. Felix lately has been sneezing alot. Tonight I noticed there was like something stuck on his nose. You know how when you get a cold things are a little crusty. Like that. Was easy to pluck off. His nose is runny too. :( I need help here. I know it is not Chiltious or whatever it is called. Please help...