doesn't get along with the toothpaste. The guess here is that the toothpaste is creating a stomach irritation, causing increased stomach acid, and the regugitation of stomach fluids. It's doubtful the chews are causing the problem.

Try stopping the toothpaste for a few days to see if things clear up. Once they do, give puppy some food first before trying to brush the teeth. A full stomach is less sensitive to acid irritations induced by other things.