Dogs have been living with us for thousands of years. They are domesticated as opposed to their relative the wolf. However, dogs still have many instincts that wolves have and, in certain circumstances a dog will bite. We usually consider some of these reasons for biting acceptable or unacceptable, depending on the situation.
A dog defending his home and human family. We often hear and read stories about dogs defending their home and loved ones against an intruder. In these situations dogs are praised for attacking and biting someone who is trying to harm humans. We value and praise dogs that are willing to sacrifice themselves to defend their families. There are lots of dogs who act as protectors and guardians in this way.
Dogs serving as military K9s and police dogs. Dogs have many roles in the military and as police dogs. Many of these dogs are trained in Schutzhund (“protection dog” in German). Schutzhund training involves a lot of education for a dog. Most of the dogs trained in Schutzhund are Belgian Malinois and German Shepherd Dogs but there are some other breeds. A trained protection dog can attack and bite on command.
A mother dog defending her puppies. Like most species, some mother dogs will attack strangers who bother their puppies. Most people understand this concept. Don’t bother a mother dog with her puppies unless they belong to you.
A dog biting out of fear. Some dogs will bite a person out of fear. This often doesn’t make sense to people because they associate biting with aggression but a fearful dog is more likely to bite than a dog that is confident. People often feel sorry for a dog that is shy and fearful. They try to approach the dog so they can comfort it or offer it help. In fact, they are making the dog much more nervous and fearful. The more they bother the dog, the more likely the shy dog is to bite.
Dogs will bite out of aggression. Dog aggression can be directed at other dogs or at people. Both situations are serious, but it is especially serious when a dog is aggressive toward humans. This is not the same as a dog that is defending his home or a mother dog defending her puppies. With aggression a dog may snap and growl at you if you try to take a toy away from him or try to remove his bowl of food. He might growl and snap at you if you try to make him move from his favorite sleeping spot. This is a serious situation. If your dog is displaying this kind of aggression toward you or someone in your home, you need professional help. Talk to your vet and a canine behaviorist if you want to try to keep the dog. If you know the dog has these problems before you get him, it is usually a good idea to pass on the dog and get a different dog. These are serious issues and not always easy to overcome.
As you can see, a dog biting can be good or bad, depending on the circumstances.