Saturday, January 26, 2008

Canine bite force

I've added a PubMed study on canine bite force, the only one of its type that I've been able to find: Measurement of bite force in dogs: a pilot study.

The abstract:

A force transducer was developed to measure bite force in dogs. A total of 101 readings was obtained from 22 pet dogs ranging in size from 7 to 55 kg. Bite forces ranged from 13 to 1394 Newtons with a mean for all dogs of 256 Newtons and a median of 163 Newtons. Most measurements fell within the low end of the range, with 55% of the biting episodes less than 200 Newtons and 77% less than 400 Newtons.
1 newton = 0.224808943 pounds force, so 1394 newtons would be 313.38 pounds force, according to The dogs in the study ranged in weight from 15.4 lb to 121 lb.

From an Animal Planet news story:
Sept. 15, 2003 — Cheetahs chomp hard and even humans can bite through an ear, but one animal reigns supreme when it comes to possessing the strongest bite — the alligator.

American alligators, Alligator mississippiensis, have the most powerful bite force ever measured. According to a recent study published in the Journal of Zoology of London, alligators snap their strong jaws shut with a force of 2,125 pounds, or with about as much force as a mid-size sedan falling on top of someone.
"Bite force is linked to the size of an animal," explained Kent Vliet, a University of Florida zoologist who headed up the study. "Since the report was published, we measured the bite of a wild gator, even bigger than Hercules at 13 1/2 feet in length missing the end of his tail. He bit down with a force of 2,960 pounds."
To put the record measurement into perspective, hyenas, which are bone-crushing mammals, have a bite force of 1,000 pounds, slightly more than the 940 recorded for lions. Dusky sharks manage 330 pounds of force, and a common dog, the Labrador, bites with 125 pounds of force. Humans surprisingly beat out the pet dog, and measured in at 170 pounds of force.
When Brady Barr measured the bite force of various animals for a National Geographic program, a hyena again was measured at 1000 psi pounds of force. A lion's bite force measured 691, a shark 669, and a Rottweiler 328 psi pounds of force. A German shepherd came in at 238, and a pit bull's bite was measured at 235 psi pounds of force. As far as I can tell, there are no studies of any kind, peer-reviewed or not, showing canine bite force to measure more than the 328 psi pounds of force recorded by Brady Barr. If you know of any, please share.

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Anonymous said...


Anonymous said...

Pounds of force, not pounds per square inch(psi)

Anonymous said...

a mastiff 528 !!!!!!

Anonymous said...

Saw study on animal planet, mastiff bite was 552 pounds of force, double that of the german shepard

Anonymous said...

I believe I saw the same show on the Discovery channel others have and the Mastiff's bite force was 556 lbs as best I recall. What they called a 60 lb American Bulldog, which was actually a Pit Bull, ( it looked like one and American Bulldogs are commonly much larger) measured 325 lbs I believe. They also measured a Malinois, and a Dutch Sheperd, but I don't recall those measurements.

estabon2 said...

I doubt brady barr as a scientist and an expert would screww up the name of the breed ( as well as NG's research staff) but if it's any cosolation the top line of the ApBt snout is smoother and differs slightly- you can see a heavy brow line w/ th AB as well as the more pronounce eye sockets with the AB - the APBT the eyes are more recessed as well - smoother eye sockets less boney- body structure is very similar in looks- it would be interesting to see the stats of a 115 - 120 lbs. the boarboel is in my opinion the most athletic and healthy of giant mastifs and very glad to see it represented-it;s not a historical analogue like whats hapened to most of the other mastiffs.

Anonymous said...

What you will say about the ''Turkish Kangal'' - about 740lbs and more...?

Anonymous said...

Domestication resulted in lowered bite force on the principle of use and disuse. Same as in man who lifts weights, gradually loses strength upon cessation of training. Wolves being non-domesticated, retained jaw power, and I have seen texts claiming 1,500 pounds for large wolf. Having seen the amazing size of some larger wolf skulls, I can believe it. It's commonly known a 55 pound coyote can bite as hard as a large German Shepherd, and wolves frequently crack open large bones for marrow. Determining bite force is a potentially risky venture for the curious.

Anonymous said...


jetchomenh said...

the last one who posted, alligators do, gators in 12 feet achieved a bite force over 2,900, that croc was over 16 feet in length, and has 5,000,not 6,000 and crocs live in countries with animals bigger than crocs or gators themselves, so they need to bite more, as of gators which live in countries (and the strongest bite of an alligator, is on america)have animals not more than the size of those african ones.therefore they do not need more bite force.

WD said...

There's a book by Barry Lopez written in the late 1970's.
Of Wolves And Men

He wrote "the jaws of a wolf have a "crushing pressure of PERHAPS 1,500lbs/in compared to 750lbs/in for a German shepherd" You can find this quote here:

Barry was just hypothesizing, nothing more. For some reason wolf orgs and internet sites have deleted the word *perhaps* and are spreading this misinformation on bite pressure as fact.

Wolves and german shepherds have no where near that high of a bite pressure.

Dr Barr's Bite Force 2 video has a 100 lb M wolf with a 406 psi bite force and domestic dogs with a 328 psi bite force.

More info on Dr Barr:

Anonymous said...

As far as dog breeds go, these are the top 4 breeds in order..

1) Rottweiler 328lb/sq in

2) German Shepard 238lb/sq in

3) Pit Bull 235lb/sq in

4) Doberman 228lb/sq in

The thoughts pf 600-700-1400 or anything over that is absolutely absurd. Hope this helps others in the future

Anonymous said...

Sorry, but you are clearly wrong, if you look it up there is actually a study on YouTube right now done by National Geograpic ch... Duch shep: 224-230lbs, American Pit bull terrier: 235lbs, German shepherd: 238lbs, American Bulldog 305lbs, African Wild dog 317lbs, Rottweiler 328lbs, Large Wolf 406lbs, Mastiff 556lbs... The study shows that the head size an yield a significant increase in bite strength... French & English Mastiff are said to have the largest heads in the Canine family, equaling the size of a polar bears head.

Reference link:

Anonymous said...

WD complained about unscientific methods of some, then what did he do? He proceeded to also use unscientific methods. The video he mentioned of a wolf with 406lbs bite, was of a"nip," not a bite. Just as the hands can squeeze more pounds on a scale than the fingers alone, so too is bite power properly measured by testing the jaws on the large crushing teeth---not the forward teeth. The wolf did not have a crushing bite applied in the video; so his methods are at least as flawed as those he complains about. Principle of use and disuse still governs! Domestic dogs are fed by humans, with dry kibble and canned food. Wolves have to break bones in many cases to bring prey down. If a 141 pound weightlifter is stronger than an average 250 pound man---and he is---why shouldn't a wolf be stronger than domestic dogs, usually smaller?