Dog nipping problems happen for a variety of reasons. Nipping may simply be a play behavior or can be the beginning of a more serious problem stemming from aggression. Identifying the circumstances that motivate dog nipping can help you establish the cause of the problem and resolve it.
Puppy Nipping
Nipping is part of normal puppy play. Puppies enjoy wrestling with one another and until they are taught some alternative play activities, will often bite and nip their human playmates as well. Even though nipping is a natural behavior it should not be encouraged. If your puppy nips at your hands or clothing you should immediately stop playing with him and ignore him. This will let him know that you do not enjoy this activity and will not participate. Teaching your puppy not to nip and bite early in his life will keep him from displaying this behavior as an adult when he may inadvertently hurt someone.
Adult Dog Nipping
Adult dogs will most often display nipping as an attention seeking tactic. Nipping often accompanies behaviors such as barking and jumping. Speaking to your dog, shouting at him or pushing him while he is jumping and mouthing will only reinforce this behavior. If your dog nips at you when you arrive home, create a place to confine him while you are away so that he cannot accost you at the door. Refuse to open gates or doors until your dog has all four paws on the ground.
Aggressive Dog Nipping
Some dogs will nip when they are guarding a valued resource such as food or their home. Territorial aggression should be addressed right away with training and behavioral modification. Nipping can quickly develop into biting if the behavior is tolerated or accidentally encouraged. It is natural for a dog to protect his food and home, but you will need to establish that you are his leader and there is no need to protect you from house guests. Do not become aggressive with your dog when working to resolve this issue. It is often best to consult with a professional about aggression issues to establish an effective behavioral modification plan.
Physical Causes for Nipping
If your normally laid-back dog suddenly displays snapping or nipping behavior there may be an underlying physical problem. Have your dog evaluated for injuries or illness under these circumstances. Pain and chemical imbalances can cause even the most tolerant dog to nip or display other uncharacteristically aggressive behavior.
Nipping Behavior with a Genetic Link
Many dog breeds have a predisposition for nipping. Herding breeds may nip as they try to get a "stray" human back in with the group. Terriers may become very aroused by play or other stimulating circumstances and will nip as their natural hunting behaviors are brought out. Guard dogs were bred to protect and some situations may motivate them to nip as a warning to perceived dangers. Early socialization and consistent training will usually curtail dog nipping before it causes a problem even in breeds that may be prone to this behavior.