Advantage poisoning? What the devil is wrong with this dog?

I have a small (9 pounder) named Capone. Yesterday my mother put some Advantage on his back to battle his flea problem. Now he's going gaga. Rubbing his face on the floor, spitting up saliva and such, and generally just acting odd. Now I would say it's the Advantage, but Capone does like to eat whatever he finds on the floor just for giggles, no matter how sick it makes him. I've given him a bath (to get the Advantage off if that's what he was ingesting) and have tried to keep the water going in the little dog, any other suggestions? When do we call a vet?