Common Reasons Why Dogs Bite

Every year in the United States, 800,000 dog bites are severe enough to need medical treatment; 17 are fatal. Fifty percent of all American children are bitten by a dog before the age of 13. Literally every dog has the potential to bite.

Children are the most common victims of dog bites, followed by senior citizens, according to the American Veterinary Medicine Association (AVMA). Its website also has an excellent list of teaching points for children about dog safety, including not to approach unknown dogs, never to pet a dog without getting permission from the dog’s person and what to do if attacked. Go over them so you can share them with kids you know. You may learn something yourself that might ensure that your own or someone else’s dog doesn’t get into trouble over something that could have been prevented. It’s worth a few minutes of your time.

Luckily for us, most don’t. Understanding what causes this phenomenon might help you to avoid becoming next year’s dog-bite statistic.  The following are a few common reasons why dogs bite.

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Dominance aggression

In cases of dogs who bite due to dominance aggression, members of the dog’s human family are most often the victims. Innocently attempt to move a dog off the bed to change the linens; push down on his rump to ensure compliance with a sit command; step over a dog who’s resting inconveniently in the doorway and the dog erupts in a “you’d better not do that” vocal warning, followed by a bite.

In each situation, the dog believes that he is in charge – that his humans have not earned the status to tell him what to do. Dominance aggression is most commonly – but not exclusively – seen in unneutered males and in confident breed types, such as rottweilers, chow chows, Lhasa apsos, English springer spaniels, Old English sheepdogs and Rhodesian ridgebacks, to name but a few. Obedience training as early as possible can abate a dog’s tendency toward dominance aggression, but dogs who are naturally and intractably dominant aggressive must be closely monitored and kept clear of situations known to trigger the negative behavior. Hollywood trainer Shelby Marlo, author of “Shelby Marlo’s New Art of Dog Training: Balancing Love and Discipline,” states, “Management is underrated. There is nothing wrong with knowing the dog’s limitations and living within those boundaries.”

Protection of valuables

The protectiveness some people seek when acquiring a dog can prove to be a liability. Some dogs believe the only way to protect their valuables is through an act of aggression. A dog’s list of valuables may include food, toys, territory (a house or a car) or even their human family members. Dogs have been known to “protect” one family member from another, driving crying children away from their mothers or chasing amorous husbands out of bedrooms.

The protection of territory is most often seen in males of guarding/herding breeds, such as German shepherds and rottweilers, while certain cocker spaniels and Labrador retrievers – females more often than males – put on ferocious displays over toys and chewies resulting in punishing bites to hands and faces.

Again, early training and/or lifelong management are the only solutions.

Fear aggression

Who knew? Little girls who love all things cuddly can be threatening — or so it seems to our German Shepherd, Tucker. He is generally a submissive guy. Yes, he barks a lot, but the other end is wagging, so it seems to be his way of saying hello. The only time I’ve seen him growl at someone is when a couple of fourth grade girls rushed toward him, wanting to pet him. And thereby hangs my lead-in to saying a bit about National Dog Bite Prevention Week, which is this week, May 19-25, 2013.

Tucker might succumb to fear biting when approached suddenly by rowdy little kids.
Dogs bite for many reasons. For Tucker, it’s the fear factor. Those scary little girls frightened him. Some dogs have territorial issues, while others might not feel well. I understand this. I sometimes would like to bite someone’s head off when I don’t feel well.

The fear aggression response is most often directed toward strangers. Veterinarians learn early in their careers: when in doubt, muzzle. Like people, dogs are naturally fearful of unfamiliar and potentially threatening situations. A dog raised in a quiet adult household will be distraught by noisy, fast-moving youngsters. The dog may bark and lunge to drive them away and deliver a stinging nip to children who do not heed the warning.

There is no particular breed or gender predilection for fear aggression, but these biters commonly lack early socialization to a wide variety of people and experiences. ASPCA Vice President of Behavioral Medicine, Amy Marder, V.M.D., states that “with a dedicated owner and a responsive dog, fear aggression can be greatly improved.”

Maternal aggression

The first two to three weeks after a female dog gives birth, her puppies rely on her for all they need to survive: warmth, nutrition, stimulation to prompt elimination and protection. Even the most outgoing, well-trained dog may show signs of maternal aggression if she feels her newborns are at risk. No training is indicated here, rather an awareness of the new mother’s innate need for a safe space. By limiting visitors to the whelping box to one to two adult family members during those first couple of weeks, the new mother will stay relaxed and focused on the job at hand. There will be plenty of time for socialization once the pups’ eyes are open and they are toddling about under their own steam.

Redirected aggression

An attempt to break up a dog fight is the most common scenario for this category of biting. Two canine opponents are barking, posturing and biting at each other when all of a sudden hands reach in and grab at collars, tails and hind legs. The adrenaline-pumped dogs blindly whip around and land oral blows to body parts of the interrupters.

Fights are best broken up by loud noises or strong blasts of water when available. However, sometimes that is not enough. If you must lay hands on fighting dogs, stay as far away from the mouth as possible and move swiftly and decisively.

Pain-induced aggression

While pain-sensitive breeds like Chihuahuas are common perpetrators, any dog may bite if hurting, depending on the degree of pain. An otherwise gentle dog will bite a beloved owner’s hand trying to soothe, bandage or examine wounds. Like us, each dog has a unique pain threshold and tolerance. A sweet floppy-eared dog suffering from otitis externa may bite on getting his ears tousled; a dog with hip dysplasia may turn on a handler pressing down on his hips to enforce the sit command.

Of course, any dog can be provoked to bite by overly zealous physical disciplining.

Pestered beyond limits

There are dog biting incidents that don’t fit into the aforementioned categories. Perhaps a new category is required, called “Pestered Beyond Limits.” Bites in this category are often prompted by children (or adults) who simply don’t understand that even a dog has limits. Hug a sleeping dog, blow puffs of air in his face, put a rubber banded knee-sox on his nose to turn him into an “elephant dog,” ride him like a pony, stuff him inside a pillowcase just to see if he’ll fit, poke, prod, tickle him, and sooner or later, the dog will say “NO!” the only way he knows how – through a bite.

  1. There are three keys to bite prevention:
    learn to understand canine behavior
  2. take the time to socialize and train all dogs – the younger the better
  3. teach children to respect all dogs, starting with their furry buddies at home.

If you are approached by a menacing dog:

  • do not attempt to run
  • stay quiet, and remember to breathe
  • be still, with arms at sides or folded over chest with hands in fists
  • avoid eye contact


Dogs also bite when they’re playing, and frankly, it’s not a good idea to play tug of war and wrestling games with your pup. What starts as a playful nip could turn into a serious bite, particularly when it involves a child or an elderly person with fragile skin. Even offering a dog a treat with your fingers can be a problem. My dad’s neighbor offered his beloved dog a piece of meat, and lost three fingers. He was a dentist, and his mistake cost him his career. Best to put the food down or use the flat of your hand.