While it is perfectly normal for dogs to play bite and be "mouthy" with each other, it is not allowable for them to do so with humans.
Nip Nipping and Play Biting in the Bud
We need to remember that dogs do not have hands with thumbs to explore and feel their world as we do, so they are limited to the use of their mouths for these purposes. As puppies grow, they move, feel, taste, touch, smell, pick up, and drop virtually everything that they can get their mouths on or around, including their litter-mates, in order to learn about their domain. As they do this, they are taught by their mother and litter-mates what is acceptable mouthing and what is not.
If a puppy mouths a litter-mate too aggressively or too hard, the litter-mate will squeal loudly and often stop playing or interacting with the offending pup, thus punishing him by isolation. After a short period, play resumes. In this way, the puppy learns what is an acceptable level of intensity of mouthing or play-biting and what is not. Mother will also punish the puppy for overly aggressive mouthing of her teats while suckling and/or playing. She rewards him by continuing to allow him to eat or play when he does so appropriately and punishing him if he does not.
When a dog grows up and begins to live in our human world, these lessons must be reinforced by us. Humans should not be mouthed or nipped anywhere on their bodies or on their clothing.
Behave Like a Canine to Stop Puppy Biting
In order to stop play biting behavior, you should react to it the way the puppy's mom and litter-mates would.
For example, if your puppy or dog should nip your hand or mouth you too intensely, one reliable way to curb the behavior is to yell “ouch” or make a loud squealing sound and firmly say a word such as “quit,” “nice,” or “no,” which will cause him to stop and back away. If he does so, he should be praised, then rewarded by being allowed to return to whatever activity you were doing with him before the offensive behavior happened. This solution often works quickly because the dog is being treated just as he was as a puppy, and he is familiar with the responses and what they mean.
If this does not work immediately, the correction level should be raised. If you vocalize and the dog does not quit his behavior, push him away, turn your back to him, do not look at him, and walk away so he feels isolated. After a minute or two, return and begin your interaction again.
Again, if the behavior continues, you may escalate your response to include physically removing the dog from your company and isolating him in a small area for a short time. Don't use his crate for this; consider a puppy-safe bathroom or small room. This removal must occur within seconds of the offense, and the isolation must not last more than four or five minutes. Dogs live in the present and will quickly lose track of what they are being punished for after a very short amount of time.
It’s possible that these particular methods will not work with some dogs, but there are many other training techniques from which you may choose.
Any technique that involves punishments such as hitting and yelling are not only cruel but are also completely ineffective and may only serve to escalate your dog’s behavior and may actually engender aggression and aggressive biting.
If you are having trouble with a nipping dog and have not been able to solve the problem, a visit to your veterinarian, animal behaviorist, or a dog trainer is highly recommended, to ensure your safety and the safety of others.
Remember, nipping or play-biting, especially by an adult dog, can be a dangerous thing. Even a play bite can draw blood and any play bite upon a stranger is a bite in the legal sense no matter how you look at it.
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