I think Jean Marie pretty much covered it.
My little rescue boy, MaveRick, started drooling Friday night and i took him to the Animal Hospital Saturday morning as an emergency. By Saturday morning he wasn't drooling anymore and his chin wasn't wet. The vet checked his teeth and such and said he teeth looked fine, and he thinks he just had something stuck that he got out himself. He's been fine every since. No more drooling.
He was still eating, drinking, active, and no weight drops but I took him to the vet anyways.
So defiantly get him to the vet and have him checked out.