I think you are right about it being a temporal infection... I'm going to the vet tomorrow to have him checked out. Thanks for all the helpful replies.
Yesterday I noticed my jackson's lower lip had swelled up a bit in the corner. Today it's gotten worse, now he has some sort of blister... From what I've researched on mouth rot, it doesn't look like that's what he has. Does anybody know of any other possible mouth infection or what do you guys...