I have heard if you put a large heavy ball in the centre of the bowl it slows them down. There is a product sold in some pet shops specifically for slowing down eating but I can't see much difference between the ball and that product.
We have a 3/4 pyrenees dog that also did this and the only thing that fixed it is when he was accidentally fed lunch twice. Our mistake is what actually changed his eating habits. Hmmm, this may work for your pup.
