I used my Halti on my old dog, a shih-tzu mostly for dominance issues per the vet recommendation. It seemed to have no effect whatsoever!! But then again, he was a small dog... Duncan has a gentle leader and it works well for pulling when on the leash. Sometimes I put it on him in the house when he is misbehaving and he calms right down usually. I have found that it hasn't been helpful in training him at all. If it's on, he walks fine. If it's off, he's off and running....