There are many reasons dogs bite. They can be motivated by aggression, boredom, fear, or simply not knowing better. Read this entire article to try to figure out which category your biting dog fits into.
Puppies who Bite
Teething Puppies
puppies bite because their teeth are coming in and through mouth needs stimulation, and they bite in play. the teething puppy will grow out of the stage and will bite less if provided LOTS of toys to play with. Most puppies bite during play and it shouldn't be a long term problem if dealt with properly.
Puppies Who Haven't Learned Better
Puppyhood is an important time to teach appropriate play. In fact, this is a huge part of those last two weeks with the puppy's litter. Puppy's play with their brothers and sisters constantly, and when a puppy bites another puppy, that puppy yelps!! If your puppy did not stay with his litter long enough to be taught not to bite in play, you should yelp and withdraw from play whenever your puppy bites. This is the best and most natural method, but if you find this method is not working you can try the below methods:
After a bite, immediately place it in it's crate alone for just 2 or 3 minutes.
bop the dog gently on the nose and say "no bite!"
fill a small spray bottle with water and spritz the dog when he bites.
To help prevent your puppy from biting:
make sure you have lots of toys available that are "bite safe"
avoid some of the older latex and vinyl toys that look like hands or feet
never play tug-of war with your dog
never wrestle with your puppy
Teething Puppies
To help prevent your puppy from developing aggressive biting habits as an adult:
Socialize, socialize, socialize. The more time your dog spends outside of your home, and inside your home with strangers present the happier and less likely it will be to bite as an adult.
Make sure your puppy meets your neighbors and frequently invite them into your yard. Make sure you puppy is used to strangers entering his home or backyard (don't worry, when it comes to protection a well socialized dog "knows" a dangerous situation and will respond- simply having a dog will deter most criminals)
When the mailmen, delivery people, meter readers, newspaper delivery people come to your house, put your puppy on a leash and let them sniff and meet these people as much as possible. Most adults injured by dog bites are in these professions. By associating uniformed people with good things, you can help make sure your dog will never bite one.
Try to have your puppy interact with children as much as possible! Many dogs raised in all adult homes become dogs with a tendency to nip or bite children. Walking your puppy at parks with playgrounds is a great way to let your puppy play with children.
adults who bite
dogs who nip
Dogs who nip are usually dogs who never learned appropriate play as puppies. Read the section on helping puppies learn appropriate play boundaries.
It is especially important with nippy dogs never to wrestle or play tug of war. Be sure that if there are any children in the home they know appropriate ways to play with dogs
dogs who aggressively bite
Dogs who bite owners are usually dogs with unclear roles within the family. In a pack, there is a top dog (alpha) and a "chain of command". If your adult dog bites you, maybe he thinks he is top dog and feels you are trying to usurp him. Simple ways to show him you are alpha are
Not allowing the dog on furniture
not petting the dog when he comes up and "asks" (demands) it
waiting to feed the dog until after you have eaten and cleaned up your own meal
never playing tug of war with anything.
Always put toys away in an inaccessible place when you are done playing with your dog
never letting your dog go through a door before you
long down stays. Command him into a "down" tell him to "stay" and insist he stay down for 20-40 minutes. If he gets up, calmly reposition him and return to your seat. (You can do this while you watch TV)
Dogs who Bite Strangers
Deal with a dog that bites strangers by allowing the dog to meet as many people as possible. Even as an adult this is important- even more so to a dog who can be aggressive. Dogs who bite strangers usually bite out of some sort of fear. Helping your dog gain confidence in all situations will reduce the chance that your dog will bite.
If your dog is likely to bite, keep him on a leash at all times. Before visitors come to your house, explain the situation and offer them treats or small pieces of dog food to offer your dog as they enter the home. This can be especially helpful for deliverymen and meter readers.
older dogs that bite
Dogs who begin biting people in their old age are a unique problem. Most older dogs who bite do so either out of confusion and being startled, or in pain. A dog who is achy and in pain will bite when moved or forced to do something that hurts. Your vet can help control the pain and thus control the biting. Personally, I've had incredible results reducing pain in older dogs with a bio-magnetic pad.
Older dogs who bite out of confusion are usually dogs who have gone deaf or blind and react in fear when startled. These dogs are more difficult to deal with- my childhood dog was euthanized at 14 because she bit when startled. We controlled her problems for years by telling visitors to our home that her bed was absolutely off limits, and that if they pet her, they needed to talk to her and watch to make sure she was aware of them before touching her. If you dog is in this situation, it may also be appropriate to post a sign on your fence gates: "deaf and/or blind dog, will bite if startled".