Photo by Ludivine HOUDAS

Tosa Inu - Breed Profile:

Origin: Japan
Colors: Red, brindle, fawn
Size: Large
Type of Owner: Experienced
Exercise: Daily
Grooming: Occasional
Trainability: Easy to train
Combativeness: Tends to be somewhat dog-aggressive
Dominance: High
Noise: Not a barker

The Tosa Inu, also known as the Tosa Ken, Japanese Mastiff, and Japanese fighting dog, is one of the native Japanese dog breeds named after the area it originated from - the old Tosa province, now known as the Kochi prefecture. The Tosa Inu was bred by crossing the Shikoku Inu with Bulldogs (1872) and Mastiffs (1874). Later on, they were also bred with German Pointers (1876), Great Danes (1924), and Bull Terriers. The goal was to improve the quality of the breed, to make it larger and more powerful.

Physical characteristics

The Tosa Inu is massive but dynamic and flexible. The head is large and broad, with a moderately long boxy muzzle. The ears hang close to the cheeks. The neck is muscular, with an evident dewlap. The body is slightly longer than tall. The tail is thick at the base, gradually tapering to a point.
The size of Tosa Inus varies greatly; it depends on where the dog was bred. Japanese Tosa breeders have focused on dogs weighing 80 to 120 pounds, while breeders outside Japan work with dogs weighing 130 to 200 pounds.


As well as the dog's size, its temperament varies greatly depending on where it was bred. Japanese breeders devote their efforts to keeping the original Tosa's temperament: quiet and calm, yet vigilant and concious of its own strength. They want innately prudent dogs that will show their unequalled courage and power only in case of emergency. Such dogs are loyal to its master, affectionate, devoted and obedient. They need an experienced dog owner who knows how to establish proper human leadership and to satisfy the dog's natural needs. Extensive socialization at an early age is vital to prevent behaviour problems.
It's very hard to find a dog with a naturally balanced temperament outside Japan. Nowadays, even in Japan there's a tendency to aim for fighting rather than humble qualities of the Tosa Inu. Buyers should always be very careful choosing a responsible and reputable breeder who cares to promote the genuine character of the breed.

Coat and grooming

The short coat is smooth and dense. It comes in red, brindle and fawn colours. There's often a black mask on the face and small white markings on the chest and feet. Occasional brushing should be fine to keep the coat in a good condition. Drooling is noticeably less than in other Mastiff breeds.


Both the parents should have the CERF (Canine Eye Registration Foundation) and OFA (Orthopedic Foundation for Animals) certificates. This breed is also prone to bloat. The lifespan is 10 to 12 years.

Other interesting facts

In some regions of the world, ownership of Tosa Inus is restricted. The breed is illegal in Norway, Denmark, Iceland, New Zealand, Malaysia, Malta, Turkey, and Australia.