Why Dogs Bite
Christine Hibbard, CTC, CPDT
Not to put too fine a point on it, but dogs bite because they’re dogs. It’s what dogs are biologically programmed to do. Every dog has the potential to bite, no matter how well socialized or friendly. I thought it might be useful to explore the different reasons why a dog might bite.
Fear Aggression: Humans never cease to amaze me in how they approach unfamiliar dogs. In my work with the clients of fear aggressive dogs, one of the topics we have to discuss is how to keep strangers from approaching their socially fearful dog. Most people assume that a dog wants to meet them. Nothing could be further from the truth with some dogs. If a dog wants to meet you, believe me, that dog will approach you.
If you can’t tell whether an unleashed dog is interested in meeting you, the best course of action is to just wait. Don’t reach out for the dog. Don’t look the dog directly in the eyes. Simply stand there like the dog doesn’t exist and wait. Even if the dog decides to approach and sniff you, don’t immediately reach down to pet the dog. Let the dog investigate and only if the dog actively solicits your attention should you reach down and pet the dog. If the dog is on leash, please ask the owner before approaching their dog and if they say their dog is fearful or aggressive, believe them. Thank that owner and wish them a good day.
Redirected Aggression: Even though human beings engage in redirected aggression all the time, people often misunderstand this type of behavior in dogs. Have you seen athletes get into a fight and the people who try to break up the fight end up getting hit? That’s redirected aggression. If a dog “has lost his or her mind” over someone coming to the door, treeing a squirrel, or fighting with another dog and you grab that dog, you run the risk of being bitten. I recommend that if possible, you just wait for the dog to calm down before grabbing it. If you need to break up a dogfight, try not to use your hands. Use a loud noise (air horn) or a can of Spray Shield, a product that sprays citronella about 10 or 12 feet.
Possession Aggression (resource guarding): Does your dog growl or snap if you go near their food bowl, try to take their bone away, or get them off the furniture? This is possession aggression or what most dog trainers call resource guarding. We humans guard our resources fiercely. We put locks and alarms on our possessions, guard the food on our plates (especially if it’s extra tasty), and resent someone sitting in our chair or place on the sofa. Some dogs guard their resources as fiercely as we do. If your dog is guarding their resources, I highly recommend hiring a professional to assist you in performing “resource exchanges” to teach Fido that if they give something up, they get something better. You can try the macho, tough route of simply out aggressing the dog, but you run the chance of being bitten and the dog’s behavior getting worse.
Pain Aggression: Often I get a call from a client because their dog has suddenly begun acting aggressively for the first time. This is a huge red flag that the dog doesn’t feel well or is in pain. In my experience, pain issues are the most under diagnosed causes of dog aggression and dog bites. Sometimes I’m told that the dog has arthritis or hip dysplasia and when I ask what medication the dog is on for pain, I’m told none. In both of these cases, I recommend a trip to the veterinarian as quickly as possible.
Territorial Aggression: This aggressive behavior is why so many mail carriers, delivery people, and utility workers get bitten. Often, what people consider “guarding their territory” is actually a fear response when an unfamiliar person comes onto your property. Barriers such as gates or tethers make this aggressive response much, much worse. If a dog is behind a fence and you need access to someone’s property, call the person you’re visiting on the phone and have them put their dog in the house or escort you onto the property.
Dominance Aggression: While many people believe that dominance is the root of all dog behavior problems, including aggression, science doesn’t back up this view. Dominance aggression is actually incredibly rare. Dominance aggression can be identified when a dog tries to control social interactions. I’ve seen cases where the dog attacked family members whenever they tried to leave the house. I’ve seen cases where the dog nips or bites when a pleasant interaction ends (play or training with food).
There are other types of dog aggression, but the ones I’ve described above are the ones of main concern to owners. If you have questions about dog aggression, you can always contact me at christine at companionanimalsolutions.com. I’m happy to direct people to books, DVDs, web sites, or other resources to help people understand dog behavior better. Has a dog bitten you or has your dog bitten someone? Please take the time to tell us about it. Discussing dog aggression is one way we learn about it!


May 18th, 2010 at 1:12 pm
Great article! At a crowded Farmers Market, I watched a toddler approach a leashed dog. The parents and dog’s owner looked on with smiles on their faces. When the toddler’s face was 12″ away, the dog lunged and snapped. No one was hurt. The dog owner apologized and hurried away with her dog.
In my opinion, both the dog owner and the kid’s parents should have apologized. Never let your toddler near a dog unless you know that dog and have tested it yourself.
May 18th, 2010 at 1:25 pm
@Val Ann C, that must have been scary to watch! I couldn’t agree with you more. Letting children approach unfamiliar dogs (especially ones on leash) is never a good idea. I wrote an article on Preventing dog bites to children for Examiner.com: http://www.examiner.com/x-49594-Northgate-Pets-Examiner~y2010m5d15-Preventing-dog-bites-to-children
Thanks for reading Behind the Behavior!
May 20th, 2010 at 6:34 pm
I agree. I’ve seen people approach dogs when the owners have asked them not to. A friend of mine has a sweet dog who is skittish. The dog has to know you before he lets you pet him. He had trouble all the time asking people not to pet him. His dog would growl, and people would be shocked because this is a sweet looking dog. So now my friend has a vest on his dog that says, “Please don’t pet me, I’m working.” This has worked.
May 21st, 2010 at 5:48 pm
@Michele C. Hollow: Isn’t it amazing how some people react when you ask them not to approach or pet a fearful dog? I’ve recommended the “Dog In Training – Give Me Space” vest which is a great product: http://www.pawsitivedog.com/DogInTrainingVest.html
May 26th, 2010 at 1:32 pm
Good article Christine
!!! Going to share this one.
July 18th, 2010 at 10:15 am
I have a dog who isn’t aggressive, but she pees when approached and petted. I really, sincerely, appreciate the people that ask, first.
August 20th, 2010 at 8:04 am
[...] and aggression. I’ve never been disappointed. Here a are a few of my favorites: “Why Dogs Bite,” “Tips for Greeting Other Dogs On Leash,” and “What Is a Reactive [...]