Pit Bulls Do Not Have Locking Jaws

“I loathe people who keep dogs. They are cowards who haven’t got the guts to bite people themselves.” —August Strindberg, A Madman’s Diary

In A Nutshell

The American Pit Bull Terrier is perhaps the most infamous animal on the planet. Banned in many countries and highly regulated in others, rumors persist that this dog is a relentless killer. The pit bull’s most fearsome weapon is its bite; many sources assert that this dog’s jaw can actually lock in place, but in fact, the structure of a pit bull’s jaw is no different than any other dog.

The Whole Bushel

For years, a most insidious and pervasive myth has surrounded the pit bull: Allegedly, unlike any other breed of dog, its jaws can lock. Other sources assert that it has the jaw strength of a crocodile, many thousands of pounds of pressure per square inch. Both claims are fully preposterous—the strength of a dog’s bite is almost entirely contingent on the size of the skull. Thus the giant mastiffs have the most crushing jaw around. The pit bull does, however, possess huge temporalis muscles (which make its cheeks bulge on either side of its head). Studies of jaw strength indicate the pit bull’s bite is of comparable strength to other dogs its size.

How then to explain the devastating injuries this typically sweet-natured animal can inflict versus attacks by German shepherds or chow chows? According to the US Centers for Disease Control, pit bull–type dogs kill far and away more people than any other breed, with encounters often likened to shark attacks. The pit’s often devastating bite is far more a function of its determination (or gameness) than its physiology. To truly understand the pit bull, one must first grasp the concept of “gameness,” a trait for which fighting dogs have been bred for centuries. A game dog will fight despite the most grievous injuries—broken bones, hypovolemic shock, or torn flesh. A “dead game” dog will fight until the last breath has left its body.

Thus, when a pit bull secures a bite, it often refuses to relinquish its hold, even under threat of pain. Where another dog will bite and release, a pit bull will cling on relentlessly. Under more innocent circumstances, this is often demonstrated by the dogs dangling from tires in their backyards. Those who keep pit bulls often have “breaking sticks” on hand—short lengths of wood that can be inserted behind the molars of a biting dog, which will force him to open his mouth in the event of a fight.

Show Me The Proof

The Real Pit Bull: Breed Myths
Bite Force Competition (video)
Gameness Defined
What Is A Break Stick?

  • MRlC

    <3 pit bulls, THANKS MIKE

  • Kaydot Mcdiamonds

    Still doesnt explain why my friend’s pitbull had to be shot in the head and have its jaws prie open, in order for it to let go, after biting him.

    • Doc


      • Kaydot Mcdiamonds

        Nice one but you’re missing the point

    • Dumas911

      Extreme determination.

    • Kambiz Cinemaie

      Somebody should shoot u in the head!

    • Laurie

      Actually it does they are determined and in their genes to not give up so in turn where other dogs bite and release the pit simply holds on “not with a locking jaw” geeeesh

      • CJM

        So to sum it up…they do not have physical traits of a locked jaws..But they have severe determination. therefore it appears like they have locked jaws. In reality it is the dog that refuses to let go. Which makes it actually the dogs fault not his genetic build. Is this the case?

  • Dumas911

    Pit Bulls are only as mean as you make them. Tying a huge log chain around its neck, and then to a tire/cinder block is the start of making one aggressive. Then of course making them fight as well. I had a pit, and even helped rehabilitate a few for a shelter, and they can be some of the most gental, and caring dogs of all the breeds. Matter a fact the smaller breeds ie. chihuahuas, shizu, lassa’s, rat terriers, jack russells, etc.. Have been know to bite, and be more aggressive than pits. It’s all in how they’re treated from a puppy.

    • adamhs

      A bit late to the party but yeah. I’ve only ever been bitten by small dogs. I “known” a friend’s pit since he was 3 months old. He likes to hold your hand in his mouth…it’s gross and slobbery but I’ve never been afraid of him doing that. Very big, sweet, and loving dog. Not to mention a GIANT chicken…

  • Helen Magnus

    No matter how many times this myth is proven wrong, no matter how correctly or concisely, there will always be morons that believe it. *sigh*

    <3 pibbles.

  • Gabriella Fattibene

    The pit bulls I’ve known are the most gentle & loyal dogs, even those who were born into the fighting business and then rescued. The more aggressive dogs are those goddamn jack russell terriers, but pit bulls take the blame because they can cause more damage and of course, people always want something/someone specific to blame.

  • Dianne White

    I have a pitbull puppy who is about 6 months old. He and our 8 year old shepherd were playing tug over a stick. Ultimately the big dog won out and the pit became upset. She bit the shepherd and a schuffle ensued. Unfortunately this ended with the pup biting the older dog in the chest and holding on. He did let go but not after drawing some blood. Clearly I can see that I should have intervened earlier. How else can I keep this from happening again between these two?

  • JohnFMayer

    A pit bull’s jaws do not lock, and their bite strength is comparable to other dogs of their size. That’s it; all the rest of the notion that these dogs have been “programmed” through breeding is as silly as the myth you set out to rebut.

  • Darren Pellichino

    I keep reading all this talk about bred to fight and bred to be gamie. Every dog becomes attached to their family. Most will give their lives to protect loved ones. The desire to protect is something we see in nearly every animal on the planet. The drive to defend against the “outsiders” is the reason, and the foundation is animal savagery….we all have animal savagery because we are animals born from a savage planet. The fact is that there are ALOT of people who own pit bulls, and there are alot of douche-bags in the world, especially when the douche cooks and shoots meth or is a raging alcoholic…their dogs will adopt some of the personality traits. You can’t go by the recorded jaw strength because some animals will see this as a stupid thing to bite. If they were fighting to protect you they will bite way harder than the test ever recorded.