KENAI
Tosa

The breeds · working

AKC Foundation Stock Service · UKC Guardian · FCI standard 260

Tosa.

FCI 260: UTILIZATION 'Formerly fighting dog, nowadays watchdog'; Group 2, Section 2.1 Molossoid, Mastiff type; without working trial. History: Japan's dog fighting dates to the 14th century; bred as a hybrid of Shikoku-ken and Western breeds (Bulldogs 1872, Mastiffs 1874, German Pointers 1876, Great Danes 1924; some accounts add St. Bernards and Bull Terriers); named for the area where bred, sometimes called Japanese Mastiff. Japan Kennel Club: same utilization, formerly a fighting dog and now a watchdog. UKC: in Japan, Tosas are the canine equivalent of sumo wrestlers, treated with honor and ceremony; in the United States a companion dog and guardian of the home. Wikipedia: originally bred in Tosa, Shikoku (present-day Kochi) as a fighting dog and the only dog legally allowed in Japanese dog fighting; ownership restricted in some countries: regulated under the Dangerous Dogs Act 1991 in the United Kingdom (court exemption required), and banned or restricted in a long list including Australia, Austria, Cyprus, Denmark, Fiji, France, Hong Kong, Iceland, Ireland, Israel, Malaysia, Malta, New Zealand, Norway, Romania, Singapore, Tunisia, Turkey and the United Arab Emirates..

Breed sets the odds. The parents set the dog. Every number here shows its source, its spread and how sure we are. Nothing on this page is a prediction about one dog.

0INHeightdogs null, bitches null. An ideal from the standard, not a range.
80–200LBWeight, all linesbreed dogs 80 to 200 lb; breed bitches 80 to 200 lb.

The body

What the breed is built like. Registry standards give an ideal, not a range.

Height at the shoulder

dogs 21.5 to 32 in · bitches 21.5 to 32 in

Breed clubAKC

Same basis as the male row: minimums from the standards, upper figure Wikipedia's only.

Weight

dogs 80 to 200 lb · bitches 80 to 200 lb

Breed clubAKC

Same breed-wide sources as the male row; neither sex is split in any source.

Coat

FCI 260: short, hard and dense; red, fawn, apricot, black, brindle; slight white markings on chest and feet permitted. UKC: short, straight, dense and tight to the body; preferred colour a deep solid rich red; other reds and fawn, brindle, dull black, brown, black with red markings, and pied (least desirable) acceptable; black mask allowed; white penalized in proportion; wavy or long coat a fault. Wikipedia: short and smooth, often red, brindle or fawn, occasionally dull black; maintenance usually minimal.

Breed clubFCI-Standard N° 260, 1997

Shedding

Shedding 2 of 5 (AKC breed page trait score)

Breed clubAKC

AKC breed page trait score, 1 to 5: a breed-club tendency, never a measurement.

Heat tolerance

4 of 5 · FCI 260: hair short, hard and dense. UKC: coat short, straight, dense and tight to the body.

DerivedFCI-Standard N° 260, 1997

Derived from a short dense coat (4). No measured data.

The dog at home

What the breed asks of a day. The first thing most homes get wrong.

Exercise need

AKC page bands: energy level 3 of 5, mental stimulation needs 4 of 5, playfulness 3 of 5, trainability 3 of 5, watchdog/protective nature 5 of 5, good with other dogs 1 of 5, openness to strangers 1 of 5. UKC: normally tranquil, quiet and obedient with a calm but vigilant demeanor; quietly affectionate with its family, somewhat aloof with strangers; watchful of other dogs and may react aggressively to dogs it considers intruders; overt aggression toward humans uncharacteristic and highly undesirable; responds best to positive training; matures slowly, prime as late as four years. FCI 260: patience, composure, boldness and courage. UKC note: some dog aggression is characteristic of the breed.

Breed clubAKC

AKC bands are registry-page ratings, not minutes; no exercise_need_min row because no source prints a duration.

Energy

3 of 5

Breed clubAKC

AKC breed page trait score, 1 to 5: a breed-club tendency, never a measurement.

Grooming load

1 of 5

Breed clubAKC

AKC breed page trait score, 1 to 5: a breed-club tendency, never a measurement.

Grooming

AKC page bands: coat grooming frequency 1 of 5, shedding level 2 of 5, drooling level 3 of 5. Coat short per FCI, UKC and Wikipedia.

Breed clubAKC

The work

What it was built to do in the field, and what a test or trial asks of it.

Role

FCI 260: UTILIZATION 'Formerly fighting dog, nowadays watchdog'; Group 2, Section 2.1 Molossoid, Mastiff type; without working trial. History: Japan's dog fighting dates to the 14th century; bred as a hybrid of Shikoku-ken and Western breeds (Bulldogs 1872, Mastiffs 1874, German Pointers 1876, Great Danes 1924; some accounts add St. Bernards and Bull Terriers); named for the area where bred, sometimes called Japanese Mastiff. Japan Kennel Club: same utilization, formerly a fighting dog and now a watchdog. UKC: in Japan, Tosas are the canine equivalent of sumo wrestlers, treated with honor and ceremony; in the United States a companion dog and guardian of the home. Wikipedia: originally bred in Tosa, Shikoku (present-day Kochi) as a fighting dog and the only dog legally allowed in Japanese dog fighting; ownership restricted in some countries: regulated under the Dangerous Dogs Act 1991 in the United Kingdom (court exemption required), and banned or restricted in a long list including Australia, Austria, Cyprus, Denmark, Fiji, France, Hong Kong, Iceland, Ireland, Israel, Malaysia, Malta, New Zealand, Norway, Romania, Singapore, Tunisia, Turkey and the United Arab Emirates.

Breed clubFCI-Standard N° 260, 1997

The legal list is Wikipedia's alone; the cited government pages were not opened, so check current law. No source describes hunting use.

How common the problems are

Evaluated dogs skew toward breeding stock; the numbers are still the best there are.

Hip dysplasia

50.5% · 101 OFA hip evaluations, current all-data, accessed Oct 12 2026; 50.5% dysplastic (mild 33.7, moderate 15.8, severe 1.0), 47.5% normal

MeasuredOrthopedic Foundation for Animals

OFA's own breed statistics. OFA-evaluated dogs skew toward breeding stock, with normal results over-represented. Small n. Hips rank 7 in the OFA table. No OFA elbow row for this breed.

More

akc bands

AKC breed page trait scores (1-5): Energy Level 3; Mental Stimulation Needs 4; Trainability Level 3; Barking Level 3; Watchdog/Protective Nature 5; Good With Young Children 3; Openness To Strangers 1; Good With Other Dogs 1; Shedding Level 2; Coat Grooming Frequency 1; Drooling Level 3; Affectionate With Family 5; Playfulness Level 3; Adaptability Level 3.

Breed clubAKC

Fourteen AKC bands in one row; the selector reads each by name. Breed-club ratings: a tendency, never a measurement.

What to ask a breeder for

The health clearances the breed’s own club and registry name. Reference only: what to ask for, never a statement about any dog’s health.

How to read this page

Every value carries a label. Measured means peer-reviewed data on many dogs. Studied means peer-reviewed, smaller or indirect. Breed club means a club or registry states it. Editorial means expert opinion with no measurement behind it. Where two good sources disagree, both are shown and neither is averaged.

Published when the entry rests on the best information available from no fewer than three independent sources, checked by a second pass that did not write it. 3 sources on this page. Found something wrong? Tell us and the correction is logged with its date.

Also called
Tosa Inu, Tosa Ken, Japanese Mastiff, Japanese Tosa

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