The Tosa (Tosa-Ken, Tosa-Token, Tosa-Inu, Japanese Mastiff), was bred for, and has been used for many years; as a fighting dog. Historically, the tradition of dog fighting was popular in many Japanese districts, but especially in the Tosa district of Shikoku. The product of thoughtful eugenic manipulation by the Japanese; the Tosa dogs active in fighting, originally; were not the present-day incarnation. The primogenitor of the modern day Tosa was the medium sized Nihon-Inu; the indigenous Japanese dog which was originally bred to hunt wild boar, and the incorporation of Occidental breeds. In 1854, the Japanese Government repealed the National Isolation Policy, this reversal began the steady influx of foreign tourism. Increasingly, traditional Japanese dog fighting began pitting the European dogs against the indigenous, Japanese Nihon-Inu. The smaller Nihon-Inu began routinely loosing against the substantially larger Occidental breeds.

These losses were devastating for the Japanese, who viewed any defeat as dishonor. Gradually, Tosa district breeders attempted to develop a larger, more truculent fighting dog, by incorporating European breeds such as: the Mastiff, Great Dane, Bulldog, Bull Terrier, and Pointer. In 1876, the German Pointer was incorporated into the breed because of their concordant temperament, and highly developed olfactory sense; which is fundamental for predation. The Mastiff (1874), was introduced because of their exceptional musculature, and the enormity of their cranial structure. However, this incorporation produced a ponderous specimen, so Great Danes(1924), were introduced to mitigate the prodigious size with dexterity and athletecism. Fundamentally, the Bulldog(1872), was sought for its’ punitive bite, powerful front-end, and truncated-stop; while the Bull Terrier(date unknown), increased tenacity.

Although the coalescence of these breeds produced the Tosa, each successive incorporation required breeders to breed back to the incipient Tosa for a minimum of three generations; until the current breed standard was established. Nearly one hundred years ago, this cross- breeding resulted in the incipient form of the present-day Tosa. The Tosa-Inu was eponymously named for the district in Japan from which it was developed. Gradually, the Tosa-Inu began spreading to other districts in Japan as dog-fighting’s popularity grew. However, the popularity of dog-fighting was spurious, contingent upon the political view of the time.

During World War II, the Tosa’s numbers dwindled to near extinction, and few remained in Japan. However, the Tosa began to flourish in Korea and Taiwan where it had been exported, previously. After World War II, the resurgence in the popularity of dogfighting promoted the collaborative efforts of Japan, Taiwan, and Korea to resurrect the Tosa-Inu.

This collaborative effort produced an intrinsically fierce fighting animal. In the Japanese style of dogfighting, the Tosa was expected to fight soundlessly, relentlessly, and without cowering. Through selective breeding, the Japanese refined the Tosa into a large, agile, athletic dog; disinclined to barking, intelligent, and fearless.

Males are powerfully built, ranging in size from 65 cm. at the shoulder, to more than 76,5 cm; and weighing between 63,5 kg. to over 91 kg. Competitively, however; the optimal combatant ranges between 50 to 68 kg. Females are smaller in proportion. However; Japanese tradition proscribes fighting between females.

Although dogfighting in Japan has always been ensconced in pageantry and ceremony, the tradition of two handlers, simultaneously ensconced in pageantry and ceremony, the tradition of two handlers, simultaneously escorting the Tosa into the fight arena; was borne of necessity. Ostensibly, the Tosa's tremendous strength required two handlers.

The Tosa has a large, broad skull with a medium length muzzle. The neck is exceptionally strong, and generally has a dewlap, however; unlike other heavily jowled mastiffs, the Tosa is not prone to drooling. The chest is particularly broad with exceptional spring to the ribs. The thighs are well muscled with only a slight bend at the hock. The coat is short, and dense; with color ranging from red, fawn, or dull black. While the embodiment of the ideal human or canine form is rarely seen; there are stringent physical and aesthetic qualities which are narrowly defined for the Tosa. Among equal specimens, red is the preferred color. White markings are only permissible on the chest, never on the face or muzzle; and the bite must be scissor. The skeletal structure of the Tosa must be large, small bones are indicative of an inferior genetic specimen; as are any signs of timidity or reticence in temperament. The life expectancy of the Tosa is 10-12 years. The most common health problems are those associated with giant breeds; such as: joint inflammation, hip dysplasia and intestinal bloat resulting from over-exercise.

The average litter size is six to twelve pups, but because of the immense size of the bitch; owners must be vigilant to ensure that puppies are not inadvertently crushed by their mother. There are no exceptional problems associated with whelping, except; due to the contentious nature of the breed, the puppies can inflict substantial injury to littermates during play, which can often appear alarmingly atavistic.

In Japan today, dogfighting is still practiced; and the Japanese revere the Tosa as the embodiment of a warrior. Historically, the Samurai were instructed to study the Tosa during combat to learn fearlessness, tenacity, and courage. Surprisingly, the rules governing Japanese dogfights are stringent and complex, and the Japanese have ennobled Tosa dogfights with all the pageantry and ceremony of Sumo Wrestling. In Japan; the Tosa is referred to as the "Sumo" dog because of its’ great size and strength. Recondite and metaphorical, Tosa dogfights are not fought to the death. In Japan; unbridled aggression or expedient victories are discouraged in dogfighting. Anthropomorphized to be warriors, in the fight arena; the Tosa is judged: by the duration of the fight, the quality of the opponent, courage, and endurance. A combatant is more highly respected If he fights courageously and for longer durations. Those competitors with many "quick wins" will be ranked lower than the competitor who routinely lasts the duration of the 30 minute bout.


The following ranks comprise the various fight

classes in Japan:

Maegashira: Amateur fighter

Komusubi: Professional fighter, 4 rounds

Sekiwake: Fighter rising in the ranks

Ozeki: Pro fighter- 10 rounds Championship contender

Yokozuna: Champion

Yushoken: Individual tournament champion

Honorary Confirmations:

Senshuken : National Japanese Grand Champion

This prestigious title may only be given during the lifetime of the dog. The combatant must be ranked higher than Yokozuna, and chosen by judges.

Meiken Yokozuna : Warrior Grand Champion

The competitor must have three fights as a Senshuken, with a record of no less than two wins and one draw. This prestigious honor has only been achieved by thirty two dogs from among more than four hundred fifty National Japan Grand Champions.

Gaifu Taisho: Best Fighting Technique

Adjudicated to be the most effective fighting technique employed by an individual combatant in a tournament.


Surprisingly, Despite the sovereignty of the Tosa; it is rarely seen in Japan. Although the Japanese deify the Tosa, Few have actually seen one. In USA, their numbers are estimated at approximately 500. Originally, the Tosa first began appearing in the US when wealthy Japanese Nationals brought them over as pets. The breed attained notoriety, when a nationally televised program hosted by actor Jack Pallance, featured the Tosa and their legendary status in Japan. As a companion, Tosa’s are ineffably affectionate, obedient, and protective, and despite their great size; they are gentle and deferential to their owners. Intelligent and affable, they are easily trained; and because of their agility and sagacity, they have been successful in Schutzhund and therapy training. However, Tosa’s require excellent socialization, as they are extremely dog-aggressive. It is never recommended to feed the Tosa with other dogs in the family, or to purchase two Tosa’s of the same sex.

Finally; Tosa’s require experienced owners who are both physically, and mentally strong. Tosa’s should be treated with sensitivity, and physical coercion should never be used for training or correction. It should be mentioned that the Tosa’s strength will greatly exceed that of their owners; Tosa’s have been recorded at pulling over 1585 kg. Not surprisingly; because dogfighting is proscribed in the United States, physical attributes, and not fighting prowess; are the measure of the exceptional Tosa. There are many competitive avenues for the Tosa; the most notable are the American Rare Breed Association and The Continental Kennel Club. However, the Tosa is a rare and Noble dog, whose legend is no myth.

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