Rather than "No bite," I strongly, strongly, strongly urge you to teach your puppy bite inhibition instead. Bite inhibition is a "soft mouth." It teaches the pup how to use his mouth gently. Does this mean that the pup will forever be mouthing you? No; not at all. Actually, regardless of the method used, puppies generally grow out of mouthing behavior after a few months.

So why should you teach bite inhibition? Because dogs have one defense: their teeth. Every dog can bite. If frightened enough or in pain or threatened, your dog will bite. That doesn't in any way make him a "bad" dog. It makes him a dog. It's your responsibility therefore, to teach your dog that human skin is incredibly fragile. If you teach your dog bite inhibition, that training will carry over even if he is later in a position where he feels forced to bite.

A story...Ian Dunbar tells a story of a bite incident he had to assess. A Golden Retriever therapy dog was leaving a nursing home when his tail was accidentally shut in a car door. The owner went to help, and the dog delivered four, Level Four bites before she could react.

FYI, a standard scale has been developed to judge the severity of dog bites, based on damage inflicted. The scale is:

• Level One: Bark, lunge, no teeth on skin.
• Level Two: Teeth touched, no puncture.
• Level Three: 1-4 holes from a single bite. All holes less than half the length of a single canine tooth.
• Level Four: Single bite, deep puncture (up to one and a half times the depth of a single canine tooth), wound goes black within 24 hours.
• Level Five: Multiple bite attack or attack incidents
.
• Level Six: Missing large portions of flesh.

Technically, the woman received a Level Five bite from a long-time therapy dog. Dr Dunbar wasn't the least bit surprised by the bites. I mean, the dog got his tail shut in a car door! Of course he bit! What shocked Dr Dunbar was that a dog with no bite inhibition was being used as a therapy dog. "But he's never bitten before." Of course not; and barring an accident like that, he probably would never have. But an accident is just that. An accident. Unpredicted. What if it had happened in the nursing home? So how do you teach bite inhibition?

Again from Dr Dunbar, there are four stages of bite inhibition. The first two stages involve decreasing the force of the bites. The second two stages involve decreasing the frequency of the bites. The training must be done in that order, If you decrease the frequency first, the dog won't learn to soften his bite. The stages:

1. No painful bites. 90% of puppies will stop if you give a high-pitched squeal or yelp. If they stop, praise and reinforce by continuing the game. The other 10 % and puppies who are tired or over-stimulated will escalate their behavior instead of stopping. This requires you to confine the puppy or end the game. Remove all attention. It does not require any added aversive -- yelling, popping the nose or chin, shoving your hand down his throat, or spraying with water. If you end the game, you need to be able to get away from the puppy with as little fuss or attention as possible. Even negative attention is attention. It's often helpful to have the puppy tethered, so you can simply move back out of his reach. Or, have him in a confined area and simply stand up and move past a boundary. Because the getting up and moving is tough to do at the instant the undesired behavior occurs, consider using a hand signal that will always mean, "You're a jerk. Fun's over." Use it consistently when poor behavior occurs and you're going to withdraw attention. I am well aware that puppy teeth hurt, and that this step can be overwhelming. Do it when you can, and at other times redirect, redirect, redirect. Puppy mouthing is a 100% natural dog behavior. It's not dominant. It's not meanness. It's a puppy being a puppy. When it's too much, either redirect or end the game. Aversives are confusing, unfair, and unnecessary.
2. Eliminate all pressure. You want to gradually shape the dog to "gum you to death." Service dog trainers do this routinely, because service dogs often have to use their mouths to manipulate human limbs. Basically, you do this gradually. Set a limit of how hard the dog can bite. If he bites harder, yelp. Gradually set your limit for softer and softer bites. Remember to do this gradually. A big jump in criteria is confusing and frustrating to the dog.
3. When I say stop, you stop. Teach cues for "Take it," "Leave it," and "Drop it." You need to be able to both start and stop the game on your terms.
4. You may never touch a human with your muzzle unless invited. Basically, this is just taking stage three to complete stimulus control.

None of these stages require anything more aversive than time outs or withdrawal of attention. When teaching these behaviors, put your hands in your dog's mouth all the time. Get him used to your being there. Make sure you can open his mouth and examine his teeth -- the vet is going to do that, and you should prepare your dog. Play mouth games. Teach your dog never to touch an object in your hand unless invited. Make sure he knows that when he is invited, he is never to bite both the toy and your hand at the same time.