Kaiser is now 9 months old and he still sometimes "mouths" but he's vastly better than he was. Previously though, you would pull your hand out and his teeth will scratch or cut you, even though he didn't apply biting pressure and his intentions were mischievous and not aggressive. It's certainly something that needs dealing with. Vizslas are so playful and we were forever telling Kaiser off about this. Lately though, when he does it, we turn on him and shout, "NO!!!". Try to react like his mother would and put him in his place. When a puppy nips his or her mum, the mother will, in no uncertain terms, let them know who's boss. This is essential to establish to fact the they need to be gentle when using their mouths and teeth. Dogs know that chewing a bone or scratching/biting a sensitive area of their body requires completely different levels of dexterity. The same applies to us. They need to know they have to be gentle.