Skip to content

Do Pit Bulls Get Lock Jaw

↯ Key takeaway points

  • Dogs can contract a medical condition called tetanus, which can cause "lockjaw," typically through a puncture wound.
  • There is little evidence suggesting pit bulls have the ability to “lock” their jaws.
  • The misconception likely came from the breed's origins in bloodsports where they needed to hold onto bulls to avoid being flung.
  • All dog breeds have the same jaw structure that moves in opposition to each other.
  • Bite force varies among dog breeds by size, and there is no definitive data on the true bite force of the American Pit Bull Terrier.
Written by Jay
BsC (Hons) Animal Behaviour & Welfare graduate with a passion for advocating for misunderstood animals.
Zoo and wildlife doctor in veterinary medicine passionate about animal welfare and preventive medicine.
Published on
Thursday 1 December 2022
Last updated on
Friday 26 May 2023
Do Pit Bulls Get Lock Jaw
This page may contain affiliate links. We may receive a commission if you make a purchase using these links.

Many pet owners wonder if pit bulls have locking jaws. This is a common concern, as there is an ongoing debate about the safety of owning this breed. However, there is no scientific evidence to suggest that pit bulls have a locking jaw.

To understand why this myth exists, it’s important to look at the anatomy of pit bulls. Let’s explore this topic together

Do Pitbulls Jaws Lock?

The lower jaw of your dog is called the mandible, and it is split into two parts that meet at the front through the mandibular symphysis. The upper jaw, also known as the maxilla, is fixed and cannot move. When your dog bites, its upper and lower jaws work together by moving in opposite directions. Every breed of dog has the same jaw structure, although their bite force may vary.

Contrary to popular belief, the American Pit Bull Terrier does not have any unique jaw anatomy that allows it to lock its jaws. This myth likely originated from the breed’s past in bloodsports, where they were praised for their ability to grip and hold onto animals. However, other breeds were also utilized for this purpose due to their similar skills. Recent studies show that the pit bull “type” group does not have a more dangerous bite than other breeds.

In conclusion, the American Pit Bull Terrier does not have the ability to lock its jaws. This misconception is a result of a lack of education and media sensationalization about the breed. However, dogs of any breed can develop a condition called “lockjaw.”

Lockjaw Syndrome

Lockjaw is a common term for tetanus in dogs. This condition is caused by a toxin that is produced by the bacteria Clostridium tetani. Your dog can contract this bacteria when it enters through a wound. In the environment, spores of this bacteria are widespread, surviving for years in dust and dirt. Once the bacteria enters a low-oxygen environment, such as a puncture wound, it rapidly reproduces and produces tetanospasmin toxin. From here, the toxin enters the nerves and travels into the brain and spinal cord. It can take 5 to 10 days for this to take place. However, symptoms can develop as early as 3 days after infection.

Lockjaw Syndrome Symptoms

In dogs, lockjaw or tetanus takes two forms. The first is localized tetanus, which is the most common. Your dog might develop rigid muscles in the area close to the wound. As well as this, tremors can develop. In contrast, generalized tetanus affects the wider body. This form is the reason for the “lockjaw” name. The muscles of your pet’s face are often affected, causing them to hold their jaws rigidly shut.

A dog with this form of tetanus may be unable to swallow properly, leading to issues with eating and salivating excessively. Muscle spasms in the forehead can cause a wrinkled appearance, and the lips may be held back in a “smile” appearance. In general, your dog may walk stiffly with its tail held up, find it difficult to breathe, and have a fever due to constant muscle contractions.

Pitbull’s Bite Force

The “pit bull’s” bite force is a point of contention for proponents and opponents of keeping these “types.” However, as we will discuss, there is currently little data on the true bite force of the American Pit Bull Terrier. When researching the APBT’s bite force, you will likely find sources suggesting that these dogs “lock” their jaws when biting. Others will say that they have the most powerful bite force of any breed, both of which are simply untrue.

Measuring Bite Force

Unfortunately, little data conclusively tells us the exact bite force of the American Pit Bull Terrier. Statistics range massively from source to source. Plenty of sources misrepresent the APBT as other, similar breeds, leading to muddied information. In fact, it’s difficult to accurately measure the bite force of a dog for several reasons.

Direct measurement of a dog’s bite force has been done but is highly variable due to the dog’s volition, situation, and specific measurement technique. Bite force has also been measured using anesthetized dogs. But, of course, these results may not be reflective of a dog’s true bite force during normal activity. Other factors like oral pain, muscle atrophy, and misaligned teeth can also affect a dog’s bite force.

Size vs Bite Force

What we do know, without a doubt, is that the breed size affects the bite force in dogs. One study published in 2009 found that the bite force in dogs is strongly related to a dog’s overall size. Another study published in 2018 backs this up, suggesting that a dog’s size and weight are the primary factors affecting a dog’s bite force.

Many other factors make up a dog’s bite force, though, including oral pain, malocclusion, and muscle atrophy. One dog of a breed may have a stronger bite force than others with these factors in mind. Some breeds have marked size differences, too – for example, we see a significant difference in Poodles, with sizes ranging from Toy to Standard. Some dogs won’t even meet their breed standard, standing too short or too tall – do we include these dogs in our data?

“Pit Bull” Bite Force

According to National Geographic’s Dr. Brady Barr, the “Pit Bull” has a bite force of 242 pounds per square inch (PSI). In contrast to the German Shepherd and Rottweiler, the “Pit Bull” came last in its bite force power. To compare this result to other animals, humans have an average bite force of 120 PSI, white sharks an average of 600 PSI, and crocodiles an average of 2,500 PSI.

It’s important to note that “pit bull” is not a breed in itself. Rather, it is a generic term that describes a “type” of dog based on physical appearance. What classes as a “pit bull” can come down to characteristics found in more than 20 unique dog breeds and far more mixed breeds. So, assigning bite characteristics to “pit bulls” in general is a difficult and muddied proposition due to the sheer number of dogs that can be classified as “pit bull” types. Even “bully-type” and “bulldog-type” dogs find themselves mixed into the range of dogs in bite force discussions. However, there is only one “true” pit bull – the American Pit Bull Terrier.

Is Shaking More Dangerous Than Lockjaw?

The “bite and shake” behavior is something that many dogs are capable of, including when playing with toys like stuffed animals and ropes. This type of biting was selectively bred in the American Pit Bull Terrier (APBT) for bloodsports, and it’s thought to be a trait that was also present in the common ancestor of all dogs, the wolf.

In the wild, all wolf species shake their prey to kill it quickly, and this behavior can be seen in our pets when they play with toys that mimic prey. It’s hard to say definitively if the APBT is more likely to engage in this behavior than other dog breeds without factual research on the matter.

Unfortunately, much of the information available about the APBT’s bite force and bite style is biased and lacks solid research. It’s important to be cautious when looking for information about breed risks, as many sources contain rhetoric, omissions, emotionally-loaded language, and exaggerations based on inaccurate statistics.

Finally, it’s a common myth that pit bulls have “lockjaw.” However, this is not true – no breed has special characteristics that allow them to lock their jaws in place. There is a medical condition called tetanus that can cause “lockjaw,” but this can affect any breed of dog

Instinctive Behavior

In the wild, all wolf species will shake their prey to quickly and easily kill it. It is thought that the intense shaking of the head aids in snapping the neck of their prey. The faster the kill is done, the quicker they can eat, which is crucial for survival in a competitive environment. This behavior shines through in our pets when they engage in play, especially with toys that mimic prey, like squeaky toys and stuffed animals. As such, any dog breed will display this instinctive behavior – and it’s hard to say definitively if the APBT is more likely to engage in it or not without factual research on the matter.

Research on Bite Style

It’s worth noting that many sources discussing the bite force and bite style of the APBT are biased in some regard. Many discussions contain rhetoric, omissions, emotionally-loaded language, and exaggerations based on inaccurate statistics. In other words, research is currently lacking in this department, and some sources will provide unsound information on breed risk.

So, do pit bulls get lockjaw? The quick answer is no. This breed “type” has no special characteristics that would allow it to lock its jaws in place. However, there is a medical condition sometimes known as “lockjaw” that all breeds can contract, better known as tetanus.

Leave a Reply

Your email address will not be published. Required fields are marked *