Posted in Working Group

A Breed Standard is the guideline which describes the ideal characteristics, temperament and appearance of a breed and ensures that the breed is fit for function with soundness essential.  Breeders and judges should at all times be mindful of features which could be detrimental in any way to the health, welfare or soundness of this breed.

UTILIZATION: Formerly fighting dog, nowadays watchdog.

Japan has a long history of dog fighting, beginning in the 14th century. With such a history in the background, this breed was produced as hybrid of Shikoku-ken and Western breeds. Named after the area where they were bred, these dogs are sometimes called ‘Japanese Mastiffs’. The Western dogs used for creating the breed were Bulldogs (1872), Mastiffs (1874), German Pointers (1876) and Great Danes (1924) all of which were used to improve the breed by sequential mating. According to some accounts, St. Bernards and Bull Terriers were also involved but it is not known in which years they were used. The Tosa’s established features of stamina and the fighting instinct typically found in Mastiffs may be attributed to the involvement of such breeds.

Large-sized dog with a stately manner and robust build. The dog has hanging ears, short hair, a square muzzle and hanging tail thick at the root.

The temperament is marked by patience, composure, boldness and courage.

Cranial Region
Skull - Broad.
Stop- Rather abrupt.
Facial Region
Nose- Large and black.
Muzzle - Moderately long. Nasal bridge straight.
Jaws - Upper and lower jaws strong.
Teeth - Strong with a scissor bite.
Eyes - Rather small, dark brown in colour with a dignified expression.
Ears - Relatively small, rather thin, set high on the skull sides, hanging close to the cheeks.


Muscular, with a dewlap.

Withers - High.
Back - Level and straight.
Loins - Broad, muscular.
Croup - Slightly arched at the top.
Chest - Broad and deep, ribs moderately sprung.
Belly - Well drawn up.

TAIL: Thick at the root, tapering towards the tip, reaching the hocks when let down.

Shoulder - Moderately sloping.
Forearm - Straight, moderately long and strong.
Pastern - Slightly inclining and robust.

Muscles very developed. Joints of stifle and hock moderately angulated, strong.
Feet: Tightly closed. Pads thick and elastic. Nails hard and preferably dark in colour.

GAIT: Robust and powerful.

Hair - Short, hard and dense.
Colour - Red, fawn, apricot, black, brindle. Slight white markings on chest and feet are permitted.

SIZE: Minimum height at withers for Dogs: 60 cm, Bitches: 55 cm.

Any departure from the foregoing points should be considered as a fault and the seriousness with which the fault should be regarded should be in exact proportion to its degree and its effect upon the health and welfare of the dog.
Thin bone
Snipy muzzle
Slightly overshot or undershot bite.


Aggressive or overly shy.

Any dog clearly showing physical or behavioural abnormalities shall be disqualified.
Extremely overshot or undershot bite


Male animals should have two apparently normal testicles fully descended into the scrotum.

Only functionally and clinically healthy dogs with breed typical conformation should be used for breeding.