Tosa (Tosa Inu, Japanese Mastiff)

Country of origin:
Height (cm):
min 55
Weight (kg):
Life span (years):
red, fawn, apricot, black, brindle
very large
Hair length:
Recognized by:
FCI code:
Good with kids:
Download standard:
Pros Cons

  • excellent watch and guard dog

  • moderate exercise requirements

  • even-tempered

  • independent and wilful

  • not for a novice owner

  • aggressive to other dogs

  • not for a family with small kids


The Tosa Inu (Japanese Mastiff) is the Japanese breed, which represents a massive and intimidating dog with powerful protective instincts. The dog was originally used for canine fights but nowadays it predominantly serves as a trustworthy and fierce guardian for personal as well as territorial protection.


The Tosa Inu has existed in Japan for almost thousand years. It was invented on the island of Shikoku in the area called Tosa Wan from which the dog got its name. Originally it was primarily bred for dog’s fights, which were popular in Japan since the XIV century. Fighting rules stipulated that the dogs should keep silence and shouldn’t flinch during the combat. The Tosa suited perfectly for this role and used to be a fearless and uncompromising fighter. The dog was oftentimes described as the «Sumo wrestler of the dog world».

The original Tosa Inu belonged to the Spitz (Nordic) type of dogs. In the XIX century the western breeds were actively imported to the Japan. In the period between 1868 and 1912 the Tosa was crossed with number of western dogs including the German Pointer, the Mastiff, the Great Dane, the Bulldog, the St. Bernard and the Bull Terrier. These breeding practises helped to improve the Tosa’s power and size and made it even the more ferocious fighter.

The hardships of the Second World War brought a devastating effect to the Tosa Inu’s population. The human being experiencing problems with food supply let alone huge fighting breeds as the Tosa. Several specimens were covered up on the Hokkaido Island so they wouldn’t be put down. These members made it through the war times and gave enough offspring to move the breed from the brink of extinction. Subsequently it became one of the treasured native Japanese breeds.

In the modern world dog’s fights are prohibited by the law but the Tosa Inu is still used in illegal pit fights somewhere in remote villages of Japan. In most cases it is kept for its excellent qualities as watch and guard dog but it’s not greatly favoured as companion dog. Moreover this breed is considered to be extremely dangerous in some countries and it’s not permitted for home keeping. (List of Banned Dogs by Countries)

The United Kennel Club (UKC) granted its recognition to the Tosa Inu in 1998 and subscribed it to the group of guardian breeds. The breed has an access to the American Kennels Clubs’ (AKC) events (for instance, obedience trials) but it hasn’t yet got an acknowledgment of this club.


The Tosa Inu is a large-sized dog with stable and even temperament and it’s deemed to be loving and devoted to its family. Having said that this dog is a poor choice for a novice dog owner since it requires a great deal of early socialisation and obedience training to become disciplinable and polite member of the society. The breed is generally ok with children providing it has been brought up with them from the puppyhood. However it won’t make up a good playing mate for a toddler due to its prominent size. The harsh games should be avoided as much as possible since they can arouse its fighting drive.

When the Tosa Inu has undergone proper socialisation it will treat strangers with due respect but it will still prefer to keep some distance. It has a high potential of becoming an excellent guardian dog, which intimidating appearance is usually enough to scare off a possible intruder. The dog has a strong need to protect its territory and it will consequently become a wonderful watchdog without propensity to excessive barking.

There are pretty good chances that the Tosa Inu will be quite tolerable towards other home pets if they have been raised together. At the same time stray cats are at a great danger in the presence of this dog so it should be always led on a leash.

The Tosa Inu was bred and trained to be a fierce and relentless participant of dog fights therefore it has big issues with other canine animals. Make sure that you have taught your dog the civilized forms of communications with other dogs and try to avoid the dog’s confrontation by any means. The Tosa is an immensely powerful breed and will win most of fights with sad consequences for its opponents.

Health Problems

The most common problems for the breed include:

· canine hip dysplasia (CHD);

· elbow dysplasia;

· patellar luxation;

· skin allergies;

· obesity;

· bloat.


Grooming requirements for the Tosa Inu are pretty insignificant. The owner should brush its coat once or twice a week using a natural bristle brush or a mitt. The bathing of the dog should be perform not more than once in a three month (or as it gets dirty).

Wrinkles on the breeds’s muzzle demand a special attention and should be cleaned with soft and wet cloth on a regular basis. The rest consists of a common care: nail trimming, teeth brushing, ear cleaning. It’s crucial to get the Tosa acquainted with grooming procedures from the early age since in its adult state its unwillingness and fear of simple brush can become a substantial problem due to the dog’s impressive size.


As far as training concerns the Tosa Inu is a quick-witted and capable learner, which can show outstanding results under the supervision of the right person with correct training plan. It definitely needs very experienced handler, which has already worked with the breed. He should always display confidence and authority in order to become a recognized leader for the dog.

The dog is known for its independent and wilful character so the handler will also require a great deal of patience and persistence. Consistent and short training sessions suit the best for the Tosu. The mild but somewhat firm methods should prevail in the course of learning experience. It’s worth reminding that the dog must always know its order in the pack and that its position is always below every human family member.


The Tosa Inu has a moderate need of physical exercise. The daily walk of an hour long is a must to maintain the dog reasonably fit and satisfied. It should always be kept on a leash since the breed’s powerful fighting instinct can be easily waken up by the sight of strange dog.

A well-socialised dog can become a wonderful jogging companion. The Tosa can develop nasty behavioural patterns (destructiveness, over excitability, chewing and so on) when not supplied with sufficient amount of physical stimulation.