Hi,
I myself have a stubborn dog and he too was very nippy as a puppy and pulled alot when we go for walks. A few things that work when we walk is a gentle leader, its a muzzle looking thing but its not a muzzel you would attach your leash to this gentle leader and when the pup pulls you have more control because it attached to his snout. It takes a bit getting used to for the pup but they do help alot. Another thing I tried that worked was looping his leash (6 foot one works well or longer) around his back end to almost make a choker so everytime he pulls the leash will tighten around his lower stomache and cause some discomfort but its easier on his stomache than his neck. The leash is still attached to the collar when doing this method. hope maybe some of that helped. It took my boy 1 1/2 years to calm down and listen better
