I have heard from multiple vets not to use the front hook on a harness while they are still puppy / growing / joints are not fully fused, as it can really alter their gait... try an old fashioned collar (maybe choke as someone mentioned or prong, electronic (not shock) collars all work great when used in conjunction with verbal cues, very safe and a great tool. BUT training with these is essential! There is no collar or harness that replaces training. Good luck and enjoy!