Teaching Bite Inhibition
Please read this section extremely carefully. I shall repeat over and over: teaching bite inhibition is the most important aspect of your puppy's entire education.
Certainly puppy biting behavior must eventually be eliminated. We cannot have an adult dog playfully mauling family, friends, and strangers in the manner of a young puppy. However, it is essential that this be done gradually and progressively via a systematic two-step process: first, to inhibit the force of puppy bites and second, to lessen the frequency of puppy mouthing.
Ideally, the two phases should be taught in sequence, but with more active puppy biters you may wish to work on both stages at the same time. In either case, you must teach your puppy to bite or mouth gently before puppy biting behavior is eliminated altogether
Inhibiting the Force of Bites
The first step is to stop your puppy from hurting people: to teach him to inhibit the force of his play-bites. Physical punishments are certainly not called for. But it is essential to let your puppy know that bites can hurt. A simple "Ouch!" is usually sufficient. When the puppy backs off, take a short time-out to "lick your wounds," instruct your pup to come, sit, and lie down to apologize and make up and then, resume playing. If your puppy does not respond to your yelp by easing up or backing off, an effective technique is to call the puppy a "Bully!" and then leave the room and shut the door. Allow the pup a minute or two time-out to reflect on the association between his painful bite and the immediate departure of his favorite human playmate. Then return to make up. It is important to show that you still love your puppy, only that his painful bites are objectionable. Have your pup come and sit and then resume playing once more.
It is much better for you to walk away from the pup than to physically restrain him or remove him to his confinement area at a time when he is biting too hard. So make a habit of playing with your puppy in his long-term confinement area. This technique is remarkably effective with lead-headed dogs, since it is precisely the way puppies learn to inhibit the force of their bites when playing with each other. If one puppy bites another too hard, the bitee yelps and playing is postponed while he licks his wounds. The biter soon learns that hard bites interrupt an otherwise enjoyable play session. He learns to bite more softly once play resumes.
The next step is to eliminate bite pressure entirely, even though the "bites" no longer hurt. While your puppy is chewing his human chewtoy, wait for a bite that is harder than the rest and respond as if it really hurt, even though it didn't: "Ouch, you worm! Gennntly! That really hurt me, you bully!" Your puppy begins to think, "Good Heavens! These humans are soooooo sensitive. I'll have to be really careful when mouthing their delicate skin." And that's precisely what you want your pup to think: that he needs to be extremely careful and gentle when playing with people.
Your pup should learn not to hurt people well before he is three months old. Ideally, by the time he is four-and-a-half months old — before he develops strong jaws and adult canine teeth — he should no longer be exerting any pressure when mouthing.
Decreasing the Frequency of Mouthing
Once your puppy has been taught to mouth gently, it is time to reduce the frequency of mouthing. Your pup must learn that mouthing is okay, but he must stop when requested. Why? Because it is inconvenient to drink a cup of tea or to answer the telephone with fifty pounds of wriggling pup dangling from your wrist. That's why.
It is better to first teach "Off" using food as both a distraction and a reward. The deal is this: once I say "Off," if you don't touch the food treat in my hand for just one second, I'll say, "Take it" and you can have it. Once your pup has mastered this simple task, up the ante to two or three seconds of non-contact, and then to five, eight, twelve, twenty, and so on. Count out the seconds and praise the dog with each second: "Good dog one, good dog two, good dog three," and so forth. If the pup touches the treat before you are ready to give it, simply start the count from zero again. Your pup quickly learns that once you say "Off," he can not have the treat until he has not touched it, for, say, eight seconds, so the quickest way to get the treat is not to touch it for the first eight seconds. In addition, regular hand-feeding during this exercise encourages your pup's soft mouth.
Once your pup understands the "Off" request, use food as a lure and a reward to teach it to let go when mouthing. Say, "Off" and waggle some food as a lure to entice your pup to let go and sit. Then praise the pup and give the food as a reward when he does so.
The main point of this exercise is to practice stopping the pup from mouthing, and so each time your puppy obediently ceases and desists, resume playing once more. Stop and start the session many times over. Also, since the puppy wants to mouth, the best reward for stopping mouthing is to allow him to mouth again. When you decide to stop the mouthing session altogether, say, "Off" and then offer your puppy a Kong stuffed with kibble.
If ever your pup refuses to release your hand when requested, say, "Bully!" rapidly extricate your hand from his mouth, and storm out of the room mumbling, "Right. That's done it! You've ruined it! Finished! Over! No more!" and shut the door in his face. Give the pup a couple of minutes on his own to reflect on his loss and then go back to call him to come and sit and make up before continuing the mouthing game.
By the time your pup is five months old, he must have a mouth as soft and reliable as a fourteen-year-old working Labrador Retriever: your puppy should never initiate mouthing unless requested; he should never exert any pressure when mouthing; and he should stop mouthing and calm down immediately upon request by any family member.
Whether or not you allow your adult dog to mouth on request is up to you. For most owners, I recommend that they teach their dog to discontinue mouthing people altogether by the time he is six to eight months old. However, it is essential to continue bite inhibition exercises. Otherwise, your dog's bite will begin to drift and become harder as he grows older. It is important to regularly handfeed your dog and clean his teeth each day, since these exercises involve a human hand in his mouth.
For owners who have good control over their dog, there is no better way to maintain the dog's soft mouth than by regular play-fighting. However, to prevent your puppy from getting out of control and to fully realize the many benefits of play-fighting, you must play by the rules and teach your dog to play by the rules.
Play-fighting teaches your puppy to mouth only hands, which are extremely sensitive to pressure, but never clothing. Shoelaces, ties, trousers, and hair have no nerves and cannot feel. Therefore you cannot provide the necessary feedback when your pup begins to mouth too hard and too close to your skin. The play-fighting game also teaches your dog that he must adhere to rules regarding his jaws, regardless of how worked up he may be. Basically, play-fighting gives you the opportunity to practice controlling your puppy when he is excited. It is important to establish such control in a structured setting before real-life situations occur.
Adapted from AFTER You Get Your Puppy by Dr. Ian Dunbar