With puppies, this is rarely aggressive behavior in which the intent is to do harm. The goals of working with this normal puppy behavior are to redirect your puppy’s desire to put something in her mouth onto acceptable chew toys and to teach her to be gentle when a hand is in her mouth. You must also teach your puppy to be gentle with hands, and that nipping results in unpleasant consequences for her. Teach your puppy that nipping turns off any attention and social interaction with you. After a nip, look your puppy right in the eye, and yell, “Ouch!” as though you’ve been mortally wounded, then ignore her. Never play tug-of-war or wrestling games with your puppy if you’re having a nipping problem. These types of games encourage out-of-control behavior, grabbing, lunging and competition with you.
At first, you may need to pet or scratch your puppy for short periods of time, since the longer she’s petted, the more likely she is to get excited and start to nip.
Attempts to suppress it or stop it are unlikely to be successful unless you give your puppy an alternative behavior.
Remember that any of these three methods will probably not be effective unless you work hard to teach your puppy the right behavior by offering her an acceptable chew toy.
Nipping and mouthing hands can also be discouraged by loosely holding your puppy’s lower jaw between your thumb and forefinger after she’s taken your hand in her mouth.
A third alternative is to wear cotton gloves coated with a substance with an unpleasant taste such as Bitter Apple.
For this method to work, every time she nips your hand she must experience this bad taste.
Attempts to tap, slap or hit your puppy in the face for nipping or jumping up are almost guaranteed to backfire.