Official U.K.C. Breed Standard


The Tosa Ken is a relatively new breed. Shortly after Commodore Perry's arrival in Japan in 1854, Japanese dog fanciers began acquiring "foreign" dogs to cross with their native stock. According to the Japanese Kennel Club, the breeds that went in to the development of the Tosa Ken include, among other breeds, the indigenous Shikoku, Bulldogs, Mastiffs, German pointers and Great Danes.

In Japan,
Tosas are the canine equivalent of Sumo wrestlers and are treated with great honor and ceremony. In the United States, the Tosa Ken serves as a companion dog and guardian of the home.

The United Kennel Club recognized the
Tosa Ken on January 1, 1998.

Tosa Ken is a large, short-coated dog, with stately manner and a robust, powerful, and agile body. The body is slightly longer than tall. The head is large and broad with a boxy muzzle, pendulous flews, and clearly observable dewlap. There is wrinkling on the head, particularly when the dog is alert. Ears are of medium size, drop, and set high. The tail is uncut, very thick at the base, and tapering to the tip. The Tosa Ken may be solid colored, brindle, black with markings, or pied. The overall appearance should be that of a massive but dynamic and flexible athlete, a true canine samurai.

Tosa Ken is normally, quiet, and obedient dog with a clam but vigilant demeanor. The Tosa is quietly affectionate with its own family but may be somewhat aloof with strangers. This breed is also by nature watchful of other dogs and my reach aggressively to dogs it considers intruders. Overtly aggressive behavior towards humans is uncharacteristic of the breed and highly undesirable. The Tosa responds best to positive-enforced training methods because of an inherent desire to please its owner. This breed matures slowly and individual dogs may not reach their prime until as late as four years of age.

The head is large and blocky when viewed from any angle. When viewed from the side, the skull and muzzle are roughly parallel to one another. The stop is moderately deep and fairly abrupt, forming an angle of about 130 degrees between the line of the muzzle and the line of the forehead. The skin on the skull and foreface is wrinkled, and the wrinkles may extend down the cheeks into the dewlap. The wrinkles become more prominent when the dog is alert. Excessive wrinkling is neither favored nor penalized. Gender difference in head is slight but apparent in the bitch's head is slightly less massive and is somewhat more feminine in appearance. White markings on the head are acceptable but not preferred.
Fault: Absence of wrinkle when alert.

Guardian Dogs Group
(c) Copyright 1998, United Kennel Club, Inc.

SKULL - The skull; is large, slightly arched from side to side, and broad between the ears. Viewed from the top, the skull is 10 to 20 percent wider than it is long. There is a deep median furrow that diminishes in depth
from the stop to the occiput. The muscles above and below the zygomatic arch are well developed and powerful. The supraorbitgal arches over the eyes are moderately well defined.

MUZZLE - The muzzle is broad, blunt, and deep with a very slight taper from the stop to the nose. The length of the muzzle is equal to approximately 45 percent of the length of the head. Jaws are very powerful. The nasal bridge is straight. Lips are thick and tight in front, with dark pigment. Beginning just behind the canines, the lower lips become visible and increasingly pendulous as they reach the corner of the mouth.
Fault: Snipy or shallow muzzle.

- The Tosa Ken has a complete set of large, evenly spaced, white teeth, meeting in a scissors bite. The pigment inside the mouth is black, with a dark roof being desirable. The tongue may be pink or pink with bluish-black spotting. Judges should not penalize missing incisors provided that there is sufficient space for a full complement of incisors.
Fault: Missing premolars, level bite, slightly overshot or undershot.

NOSE - The nose is always solid black. In profile, the tip of the nose extends just slightly beyond the end of the muzzle. The nostrils are large and well opened.
Serious fault: Nose any color other than solid black.

EYES - Eyes are small to medium in size, round top slightly almond-shaped, set well apart, and rimmed with solid back pigment. Eye color is brown with preference given to the darker color. A bluish eye color in a Tosa under the age of 12 months is acceptable. Eyelids are tight although some visible sclera or very slight haw is allowed.
Serious faults: Very visible haws; yellow eyes.

EARS - Ears are of medium size, drop, and V-shaped, with slightly rounded tips. Ear leather is thin in comparison to the overall thick skin of the body. The ears are set high, level with the upper line of the skull and hang close to the cheeks. Ears are covered with short, fine hair. The ears may be the same color as the background color of the dog's coat, or somewhat darker in color. When pulled toward the eye, the ear should extend to the inside corner of the eye.
Disqualification: Cropped ears.

The neck is moderately long, thick, and slightly arched at the crest, particularly when the dog is alert. It is very powerful and muscular with a clearly observable dewlap. The skin is thick and elastic.
Faults: Dry neck; thin or weak neck; ewe neck.

The shoulders are moderately laid back, moderately angulated, and well muscled, but not loaded. The upper arm is roughly equal in length to the scapula.
The forelegs are straight and muscled, with sturdy bone, very strong and set well apart. The elbows are set on a plane parallel to the body, and move freely, neither close to the body nor turned out. The pasterns are short, powerful, and slightly sloping when viewed in profile. Viewed from the front, straight pasterns are preferred, although a slight toeing out is acceptable.
Faults: Toeing out; straight shoulders; loose or loaded shoulders.
Serious faults: Fine bone; lack of muscle; fiddle front; out at elbows; down at pasterns' knuckled over.

A properly proportioned
Tosa Ken is slightly longer (measured from prosternum to point of buttock) than tall (measured from the withers to the ground), and length of the front leg (measured from point of elbow to the ground) should be roughly equal to one-half of the dog's height. The Tosa's body is covered with thick, loose skin, especially around the throat. The chest is broad and deep, with ribs expended well back and moderately sprung. The topline inclines very slightly downward from the withers to a broad, muscular, level back. The lion is short, broad, muscular, and slightly arched, blending into a moderately sloping croup. The belly is moderately to well tucked up and firm.
Faults: Obesity; noticeably higher or lower at the croup than the withers; shallow or narrow chest; pronounced roach back, camel back, or sway back.

The hindquarters are sturdy and powerful with well-developed muscles. The width and angulation of the hindquarters is in balance with the width and angulation of the forequarters. Viewed from the side, the rear pasterns are well let down and perpendicular to the ground. Viewed from the rear, the rear pasterns are straight and parallel to one another. A
Tosa under the age of 12 months should not be penalized for standing with hocks turned slightly inward as this normally corrects with maturity.
Faults: Hocks turned inward or outward, with the exception for puppies noted above; straight stifles; over-angulation of stifles or hocks.
Serious faults: Fine bone; weakly muscled rear.

The feet are large, round, and tight. Pads are thick and elastic. Toes are well knockled and nicely arched. Rear feet are slightly smaller than front. Nails are hard and preferably dark in color. Both front and rear feet should point straight forward.
Faults: Splayed, flat, or thin feet; toeing out. The seriousness of any of these faults is based on the degree of defect.

The tail is set on as a natural extension of the topline, and is thick and muscular at the base, tapering to the tip. A "pump handle" tail is acceptable. A tail of the correct length extends to the hock. Correct tail carriage ranges from hanging naturally between the hock when the dog is relaxed, to upright with a slight forward curve at the top of the tail when the dog is moving or excited. The tail should never curl over the back.
Fault: Gay tail
Disqualification: Docked tail.

The coat is short, straight, dense, and tight to the body.
Faults: Wavy coat; long coat.

The preferred color is a deep, solid, rich red. The following colors, color combinations, and color patterns are all acceptable: All other shades of red, including fawn; any combination of red and black brinding; dull black; brown; black with red markings; and peid, which is the least desirable. Black masks are allowed without penalty. Black tipped hairs are allowed without penalty. White markings are allowed but penalized in proportion to the amount of white on the dog. White other than on the chest or above the feet is to be discouraged.
Serious fault: Any color, color combination, or color pattern other than listed above.

The minimum height for a mature male is 23-1/2" inches and 21-3/4 inches for mature females. As long as the minimum height requirement is met, no preference is given to greater or smaller size. Weight should be sufficient so that the dog presents a harmonious blending of sturdiness and substance with agility and athleticism. Males are typically larger with heavier bone and more muscle than females.

When trotting, the gait is effortless, smooth, powerful and well coordinated, showing good reach in front and drive behind. When moving, the backline remains level with only a slight flexing to indicate suppleness. Viewed from any position, legs turn neither in nor out, nor do feet cross or interfere with each other. As speed increases, feet tend to converge toward center line of balance.

Unilateral or bilateral cryptorchid. Viciousness or extreme shyness. More than four missing teeth. Bluish eye color in a dog 12 months or older' functional abnormally of eyelids or eyelashes. Cropped ears. Docked tail. Albinism.

Note: Tosas are not to be penalized for dog aggression as it is a normal characteristic of this breed. Handlers, however, may be penalized for failure to properly control their dogs.


Before we list the Tosa ranking in Japan today it is important to realize that the Tosas fight in Regional Tournaments but rankings are bestowed upon them by the National Tosa-ken Spread Association. Also, the rankings are not permanent as long as the Tosa is actively fighting.

A Tosa is judged by how long his fights last, the quality of his opponents, and his exhibition of courage, and stamina. The longer a fight endures, the more he is honored. The fight is more highly respected if both animals fight stronger for longer without kill. This is contradictory to fights staged in the United States, where a dog is more highly revered for quick win & kill. Therefore, a Tosa with many quick wins will not be ranked as high as one with only a few wins of bouts that lasted the duration.

A Tosa can earn a title but must either retire with it or maintain it. Retirement is self explanatory. A Tosa may lose a fight or two and maintain his title if the fight are good and long lasting. He may not lose many, however, before his ranking will be dropped. Contrary, if a Tosa wins too many matches too quickly, he will be forced to compete versus higher ranking dog. The Tosa who wins the longest lasting bout of the tournament will be that tournament champion. Whichever dog fights closest to the full 30 minutes wins the match. If both dogs are still combating at the 30 minutes time limit the bout will be declare a draw and neither dog is entitled to the little contested for.



Amateur Boxer Novice

Real beginner


Pro-Boxer 4 Rounder

Some experience of fighting


Dog rising in the ranks


Pro-Boxer 10 rounder

Awaiting championship


Grand Champion

Heavyweight: 1st National Japan CH. TENJOUZAN (p718 top)

1001st National Japan CH. 2nd BUNGOBANA

Middleweight; 1st National Japan CH. KOTETSU
1056th National Japan CH. ISOGAHAMA


That Particular Tournament's Champion

It doesn't matter what weight class, the dog which fights the closest to the thirty minutes time limit and wins his match.
1st Tournament CH. RAIDEN ?168th Tournament CH. KINJO


National Japan Grand Champion

Can be won only in a dog's life. He must be ranked higher than YOKOZUNA and chosen by judges. If a dog successfully challenges for SENSHUKEN he qualifies to challenge for MEIKEN YOKOZUNA. If he loses that challenge, that's it! A dog may fight once each day of tournament (Tournaments are two day events.) He may fight in only two tournaments in a one year for a maximum of four fights a year.

Heavyweight: 1st National Japan GR.CH. TOYOKUNI (p719)
196th National Japan GR.CH. 8th SHOURIKI
Middleweight: 1st National Japan GR.CH. IWATEDEN
185th National Japan GR.CH. SHIROKINJO
Lightweight: 1st National Japan GR.CH. BISHAMON
43rd National Japan GR.CH. GINJIRO


Warrior Grand Champion

He must have three fights as a SENSHUKEN with a record no worse than TWO WINS and ONE DRAW. This honor has been achieved by only thirty two dogs of the almost four hundred fifty NATIONAL JAPAN GRAND CHAMPIONS!


Best Fighting Technique

Judges decide which dog has the best fighting technique of all the dogs that fought in the Tournament.
1st Gaifu Taisho. TENRYUSHIBUKI
80th Gaifu Taisho. SHIN KUNSHO

1. As of October 1994 (pages mentioned refer to the National Tosa-Ken Spread Association Stud Book)

These rankings are bestowed upon the Tosa by a panel of judges based on the Tosas fighting accomplishments. And all rankings in Japan (Except WARRIOR GRAND CHAMPION) are issued numbers by the National Tosa-Ken Spread Association JUDGES PANEL.

Usually, Tosas fight not only within their weight classes but also within their rankings. If a dog does well or poorly, the Tosas are usually matched up to equal dogs by these judges but a Tosa owner can request his dog enter a ranking class above what he is ranked in the hopes of getting his noticed and moved up. If a Tosa is entered, a lower ranking class than what he is considered, he will loses his higher ranking and must earn it all over again - This is rarely if ever done.