I recently starting using a gentle leader for my dog and this has greatly reduced the amount of pulling he does on the leash.
A 'gentle leader' is a leash attachment that goes around the dogs mouth and snout and is attached to the dog leash. When your dog pulls, the dogs face is turned to the side making it uncomfortable for them, which causes them to stop and wait for you. With a gentle leader on, your dog can still fully open his mouth and breathe and it does not impair them in anyway.
Using a gentle leader has significantly reduced the pulling that my dog does and I highly recommend it for your dog, especially if you have a dog that pulls. Gentle leaders are also marketed under the name "Halti" in addition to "Gentle Leaders".
