Pit Bulls have locking jaws. 

NO!  The pit bulls jaws are the same as any other breed of dog!  Any Veterinarian can verify this is simply a myth.  Pit Bulls have been bred to not let go, however, their  jaws are not locked.

Prepared by: Al W. Stinson, D.V.M.
Director of Legislative Affairs, Michigan Association for Pure Bred Dogs, and the Michigan Hunting Dog Federation, and a Member of the Board of Directors of the American Dog Owners Association

The following quote was sent to me from Dr. Howard Evans, Professor Emeritus, College of Veterinary Medicine at Cornell University, Ithaca New York. We were colleagues in the veterinary college for four years. He is the author of the textbook, ANATOMY OF THE DOG, (the world’s definitive work on the anatomy of the dog). His statement was in a letter addressed to me on March 26. 2002. His quote was: “I have spoken with [Dr.] Sandy deLahunta (the foremost dog neurologist in the country) and [DR.] Katherine Houpt (a leading dog behaviorist) about a jaw locking mechanism in pit bulls or any other dog and they both say, as do I, that there is NO SUCH THING AS “JAW LOCKING IN ANY BREED.

We all agree that the power of the bite is proportional to the size of the jaws and the jaw muscles. There is no anatomical structure that could be a locking mechanism in any dog.” As a Professor Emeritus from the College of Veterinary Medicine at Michigan State University, I agree completely with their conclusion.

Pit Bulls have a 1800 PSI  Jaw Pressure.  

Wrong again.  Working with author Karen Delise (Fatal Dog Attacks) we have researched the references used for this data and have found there is no factual research to support this claim.   This myth stems from an article published in the 1989 The Journal of Trauma “Mauling by Pit bull Terriers: A Case Report” by Bret R. Baack, M.D., John O. Kucan, M.D., Gerland Demarest, M.D and E. Clyde Smoot, M.D.   On Page 519 it states:  “Pit Bulls bite with greater force than most dogs (up to 1,800lb/in2)  (4).

Reference (4) cited for this fact is:  “Dog bites in children: Epidemiology, microbiology, and penicillin prophylactic Therapy but Douglas A. Boenning, M.D., Gary R. Fleisher, M.D., and Joesph M. Campos, PhD.

However, neither the topic of bite pressure nor pit bulls is addressed or even mentioned throughout the entire article.

This case report is promoted by many people as fact, yet it’s not substantiated anywhere.

On the other hand, here is scientific evidence proving this myth is an urban legend:

Dr. Brady Barr of National Geographic (Dangerous Encounters: Bite Force, 8pm est 8/18/2005) – Dr. Barr measured bite forces of many different creatures. Domestic dogs were included in the test.

Here are the results of all of the animals tested:

Humans: 120 pounds of bite pressure

Domestic dogs: 320 LBS of pressure on avg.  A German Shepard, American Pit Bull Terrier (APBT) and Rottweiler were tested using a bite sleeve equipped with a specialized computer instrument.  The APBT had the least amount of pressure of the 3 dogs tested.

Wild dogs: 310 lbs

Lions: 600 lbs

White sharks: 600 lbs

Hyenas: 1000 lbs

Snapping turtles: 1000 lbs

Crocodiles: 2500 lbs

Pit Bulls are born to be mean.  

Not True!  Pit Bulls like all other breeds, are not born inherently mean or bad!  They can, like any other breed, become mean through lack of training, abuse, neglect and irresponsible ownership and breeding.

(From ACF) There is no scientific proof that Pit Bull’s, or any other breed of dog is dangerous. The Foundation’s collective experience and research has found the American Pit Bull Terrier is a “terrier.” All terriers have animal prey
drive, but this does not make them dangerous or vicious. The Pit Bull type dog comes from Europe and evolved from some Mastiff based breed such as with some Bulldog blood either in a pure form or to a variation of any of the many terrier and hound groups beginning with the now extinct Black and Tans Terriers and Olde English White Terriers. English and Irish immigrants imported the dogs. Unfortunately, it was discovered in the late 1800’s that if trained, the dogs could be used in the inhumane sport of dog fighting. Due to federal laws passed in the 1970’s prohibiting dog
fighting fewer dogs are now trained for the illegal sport.

The American Pit Bull Terrier is shown in the American Kennel Club
(AmStaff), United Kennel Club, American Dog Breeders Association, Canadian  Kennel Club, and the American Rare Breed Association . The American Pit Bull Terrier is shown in the conformation and obedience ring. This breed competes in weight pull events in the ADBA, UKC and International Weight Pulling Association. The American Temperament Test Society (POBox 4093, St Louis, and MO 63136 Phone 314-869-6103, in the 24 years of testing over 185 breeds of dog, rates the Pit Bull at 83.1%. This is higher than the national average for all other breeds of dog. This means the Pit Bull has the best overall temperament. The American Pit Bull Terrier also rates high in the
Canine Good Citizens Test. The Pit Bull is used for Search and Rescue and as
a Therapy dog. Our Foundation uses them along with other breeds for bite
prevention and responsible ownership classes in the Washington School
Districts.  Two US Presidents owned Pit Bulls and countless famous people
own them. In our country more families own the Pit Bull than any other dog
breed in existence. (WAFAmicus Alabama 2002)

From American Canine Foundation:
Since 1936 there have been an estimated 4.8 million registered American Pit Bull Terriers, American Staffordshire Terriers and Staffordshire Bull Terriers  that have been selective bred for companionship and conformation dog shows. These dogs are not bred for dog fighting and HSUS estimates 200,000 thousands Pit Bulls are used for illegal activity. There is no proof that the 4.8 million APBT’s are included in this figure, because the registries AKC/UKC/ADBA that register these dogs prohibit illegal dog fighting. If it could be proved that any of the registered APBT’s were involved in illegal activity, it would be less than 4 percent out of 4.8 million. There is an estimated 52 million dogs in the United States and the American Pit Bull Terrier takes up 9.6 percent of the dog population and that does not count  unregistered ones.  There is no such dog called a Pit Bull Type Dog, it would be a mix breed. (ACF2003)

Dr. Cornelia Wagner DVM, an expert on canine behavior from the University of Wisconsin, states:  BLAMING THE GENETIC MAKEUP OF THE DOG IS WRONG. (Fedderson-Peterson, D.U.(2001)  Zur Biologie des aggression des Hundes, Disch Tierarzil, Wschr 108 (3),94-101, environmental and learning effects are always stronger than genetic influence. Although certain dog breeds such as the Rottweiler and American Pit Bull Terrier have the reputation of having stronger jaws than other breeds, valuable scientific studies showing significant differences in jaw strength among breeds does not exist. In summary, the classification of dog breeds with respect to their relative danger to humans makes no sense, as both the complex antecedent conditions in which aggressive behavior occurs, and its ramifying consequences in the individual dog’s ecological and social environment are not considered.”

Will a pit bull that shows aggression towards a dog, go after people next.?

No animal aggression and human aggression are 2 completely different things!  There are many types of aggression in the canine world and they are all very different.

Pit Bulls attack more than any other breed.    

No, the statistical data on dog bites and attacks are inaccurate.  Many dog bites are never reported. There is nothing in place to track dog bites in the US accurately.

There are 25+ breeds that are commonly wrongly identified as pit bulls, Those of us who have been involved with the breed for years have trouble identifying them 100% of the time, so, we certainly can’t expect inexperienced people to be able to properly ID a dog.  That said, it leads us to believe that many of the bites that claim to be from pit bulls are in fact, inflicted by other breeds.

Here are a couple of links to tests, you try to pick the pit bull!



“Identification of individual dogs is possible on the basis of inherent and

acquired markings, the possibility of error can never be excluded.

Unmistakable identification is possible on the basis of definition of blood

groups respectively polymorphous protein and enzyme systems (Schleger and  Stur 1986), on the basis of DNA- fingerprints (Jeffreys and Morton1987

Georges et al., 1988) as well as with microchip identification (N.N.,1993)

Based on blood groups, polymorphous protein- and enzyme systems as well as DNA -fingerprints respectively canine micro satellites, the verification of

an indicated lineage of two specific parent dogs is possible in an

individual dog (Morton et al., 1987; Binns et al., 1995; Fredholm and

Wintero, 1996; ZAJC and Sampson, 1996).

Identification of a particular breed affiliation is nevertheless only

possible based on exterior markings which are defined in the breed

standards; however in an individual case the undoubted affiliation of a dog

to a breed is only partially possible.

Of course, based on canine DNA markers one can execute genealogical studies about the genetic distance between breeds or populations (Fredholm and Wintero, 1995; Okumara et al., 1996; Pihkanen et al., 1996; ZAJC et al., 1997) but affiliation of a single dog to a certain breed or the determination of lineage of a mixed breed dog of certain breeds based on canine markers is not possible according to current scientific standings (Templeton, 1990).” (Stur 2001)  (ACF 2003)

A study at the University of Washington (Bandow, 1966) shows a comparison between the shares of breeds in bite incidents in comparison with the recorded numbers. In this study, no statistical insurance regarding the deviation of breed dispersion resulted. The breed statistic, moreover, is according to the testimony of the author, to be viewed with reservation. Breed association is based on testimony of the victim who can not always in an accident situation correctly identify the breed of attacking dog, or based on the testimony of the owner who does not always state the correct breed.

As for statistics used to support the idea that some breeds are more dangerous, the numbers are misleading, said Anthony Pobderscek of the University of Cambridge Veterinary School. “There’s a problem getting records,” he said. “Golden Retrievers bite, Labrador Retrievers bite, but don’t get reported.” Dr Wagner presented the results of a study on the “dangerous dog” laws of Germany earlier this week at the meeting of the International Society for Anthrozoology in Davis, Calif. Although they look different, dog “breeds” have no more scientific basis than do “races” among humans, said canine researcher James Serpell of the University of Pennsylvania.  According to RIECK (1977), the biting dog is typically male, younger than two years, and belongs to a working dog breed (e.g. Shepherd or Rottweiler), or is for instance a Cocker Spaniel, or a Chow Chow, and originates in mass breeding in which temperament or other desired qualities of a dog are not considered in breeding. The author quotes a statistic about deaths through dog bites. In 34 death cases in 1989 to 1990, 10 cases were caused by Nordic breeds like the Husky, Samoyed or Malamute, 10 further cases were caused by Pit Bull type (mix) dogs uncertain of positive identification. Seven deaths were caused by German Shepherds, 3 by Dobermans, 1 by a Rottweiler, and 4 by other breeds.

To claim one breed is more responsible for human fatalities is impossible. Some would chose to single out the Pit Bull , due to the fact there are estimated statistics and the type of dogs that resemble the Pit Bull are such a wide variety that we find Amercian Bulldogs, Boxers, and Mastiff’s labeled as Pit Bulls. It is impossible to compare different breeds of dogs versus human fatalities.

The Washington Animal Foundation did a survey on human fatalities by dogs in 2001 and came up with these figures, Rottweiler (6); Labrador (2); Pomeranian (1); German Shepherd (2); Chow (1); Wolf-Hybrid (1); Akita (1); Doberman (1); Beagle (1); Presa Canario  (2); Pit Bull  (1); mixed breeds (6). When comparing these figures with the  human fatalities from 1975-80 by Pickney & Kennedy, Traumatic Deaths from Dog Attacks in the United States, the report identified the following as responsible for human fatalities during the study period from May, 1975 to April, 1980: German Shepherd (16); Husky (9); St. Bernard (8); Bull Terrier (6); Great Dane (6); Malamute(5); Golden Retriever (3); Boxer (2); Dachshund (2); Doberman  Pinscher (2); Collie (2); Rottweiler(1); Basenji (1); Chow-Chow (1); Labrador Retriever (1); Yorkshire Terrier (1); mixed and unknown breeds (15). One would question the accuracy of human fatalities by dogs from current reports and especially the statistics on the Pit Bull. When looked at from a more realistic point of view one would find Shepherds and other working dogs rate higher in fatalities. However, given the increasing population of dog breeds at any given time, it is impossible to compare one breed to another.

20% of deaths involve unrestrained dogs off the owner’s property, 70% involve unrestrained dogs on the owner’s property, and 10% involve restrained dogs on the owner’s property. Unrestrained dogs are responsible for a high number of dog bite reports and attacks to other animals. Over 30 breeds of dogs have been involved in 400 human deaths in a 30 year period.

In researching dog bite incident reports for the year 2000 in Pontiac Michigan, our Foundation found a high number of mixed breeds biting but no human fatalities. Chow Chows were the dogs biting unprovoked more than other breeds. We found a high percentage of teasing or tormenting of dogs which in turn caused them to bite. We found Sight Hounds responsible for deaths to other animals, yet the breeds you hear about in the media did not rate high.  We find, because of the media attention focused on specific breeds such as  the Pit Bull, that the real statistics are never brought to the attention of the general public or the politicians, which in turn does nothing to protect the safety of the public. This misinformation affects the political pressure concerning the passing of breed bans instead of focusing on passing strong dangerous dog laws that target the irresponsible owners of all breeds of dog.

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About the author

Arnold Smith

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