Pit bull problem: The owner or the breed?

seattlepi ^ | June 23, 2009 | CASEY MCNERTHNEY

[txhurl]

Once again, what biological mechanism allows an American staffordshire terrier to lock its jaws?

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I say we use the scientific method. You go witness a bulldog fight. If perchance you see any jaws lock, come back and we’ll try to unravel how or why that could have happened.

Until then you may as well be asking if tetanus (lockjaw) is a real disease.

[Immerito]

In other words, you can’t name a single biological mechanism that *locks* the jaws of a single breed of dog?

It would seem that you are determined to perpetuate a myth.

[txhurl]

What if I moved the goal posts laterally and claimed there is no amount of physical injury a bulldog will undergo that will cause it to unlock its jaws? That is, a bulldog is willing to die before unlocking its jaw?

What we need here is a biological mechanism, OTHER than asphyxiation, that will cause a bulldog to un-clamp. So far
we don’t have one, unless you’ve heard of one?

[Immerito]

Asphyxiation is not a biological mechanism, and only highlights that the jaws are not, indeed, locked.

Let’s try again. Show me the skull of any of the dog breeds identified under the umbrella of “pitbull” and show me the part of canine anatomy that “locks” the dog’s jaws

[txhurl]

Fine. Now, you have to remember that I have with my hands, unlocked two separate bulldog clamps belonging to dogs not mine, so I still hold the empirical edge, while you dance in theory.

I agree the cranial and maxillofacial anatomy of all dogs are the same. It's the muscles that control the jaws that differ greatly. Aw, I lied already. Bulldogs have wider jawsets than any other breed.

In bulldogs - and notice I'm not painting pits in any of these posts - cute little puppies are BORN with this:

This is certainly not to suggest any intentional breeding such that massive jaws are selected for in any subset of bulldogs. Coincidental at best.

Perhaps this massive jaw muscle has weaknesses... much like a swimmer might develop a muscle cramp. If a physical attribute is overdeveloped via close inbreeding, and when overtaxed, it cramps involuntarily.. certainly the swimmer didn't intend to drown because his legs wouldn't unlock.

I know my calves have cramped on me, and not a damned thing I could do about it until whatever chemicals I worked out instructed them to 'relax'.

[txhurl]

I should probably add that conditions like hip dysplasia and such probably didn’t exist in the original breeding stock. Overdevelopment of desired characteristics via too close inbreeding produces physical problems. Why couldn’t ‘inability to control jaw muscles in the short term’ be one of them?

[txhurl]

and show me the part of canine anatomy that “locks” the dog’s jaws

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Gave you a decent hypothesis, is that all you you’ll be needing this thread, Sir?

[Immerito]

That is what I have asked for all along, and you have, hitherto, been unable to name one anatomical structure which locks the dog’s jaws, rendering them, by definition, immovable on whatever is clenched between them.

[Immerito]

Muscles are incapable of locking; cramping, while a common affliction of muscles, is not the same as locking.

A rottweiler or German shepherd has greater bite force than an American staffordshire terrier, and no one makes the ludicrous argument that their jaws lock. What these breeds have in common is that they have all shared the spotlight of “Devil Dog of the Decade”. Currently, it’s the AST’s turn. In time, there will be a new culprit.

But so long as people parrot myths about dogs, this decades old problem will not be solved.

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The Locking Jaw

The most common myth about ‘pit bull’ dogs is that their jobs lock. This is untrue.

Breeds like the American Pit Bull Terrier do have very powerful jaws, and this is where this myth comes from. However, the jaw does not ‘lock’ - and you cannot get the jaw to ‘lock’ through abusive actions such as breaking the jaw. (yes, we have heard from people who believe this is how you get a ‘locking jaw’ and we have incredibly sympathy for any animals they own.)

On this topic Dr. 1. Lehr Brisbin of the University of Georgia wrote:
“The few studies which have been conducted of the structure of the skulls, mandibles and teeth of pit bulls show that, in proportion to their size, their jaw structure and thus its inferred functional morphology, is no different than that of any breed of dog. There is absolutely no evidence for the existence of any kind of “locking mechanism” unique to the structure of the jaw and/or teeth of the American Pit Bull Terrier.”

The ‘pit bull’ has powerful jaws, but they are not alone in this. This is yet another myth - that ‘pit bulls’ are more dangerous because they have the most powerful bite. Most large breeds and cross breeds have a very strong bite, and even smaller dogs can inflict a bite powerful enough to kill. Any dogs can be dangerous in the hands or an irresponsible, negligent or abusive owner.

http://www.dogwatch.net/myths/lock_jaw.html

[Poser]

“The answer is... BOTH. “

Agreed.