HOME ASIA Japanese Dog Breeds Tosa Inu

Tosa Inu

Other Names: Tosa Ken, Tosa, Japanese Fighting Dog, Japanese Tosa

Country Of Origin: Japan

Dog Group: Mastiff/guarding

Size: Large

Recommended For: Families, couples, single owners

Maintenance Level: Moderate

Lifespan: 9-11 years

Temperament: Aloof, wary, affectionate

Tosa Inu Commonly Asked Questions

Good For First-Time Owner: No

Good With Children: Yes

Good With Other Animals: Sometimes

Good With Strangers: Sometimes

Good For Apartments: No

Exercise Requirements: Daily walking

Can Live In Hot Weather: Yes

Can Live In Cold Weather: Yes

Can Tolerate Being Left Alone: Yes

Grooming: Moderate

Trainability: Moderate

Breed Overview

The Tosa Inu was originally used as a fighting dog in Japan, and as a result, it banned or heavily restricted dogs in Asia and other parts of the world.

However, much like other seemingly dangerous dog breeds, much of this reputation comes from their historical use.

Tosas can be a good choice as a family pet, but owners must be confident and consistent with training.

A Tosa will form strong bonds with its family, and aggressive behavior toward people is seen as a fault in the breed.

 Color: Red, fawn, brindle, black

 Height: 24-32 inches (both males and females)

 Weight: 130-200lbs (both males and females)

 Personality and Temperament:

 A Tosa Inu outside of Japan is a drastically different dog from one bred in its native country.

Worldwide breeders focus on larger dogs, whereas Japanese Tosas can be around half the size.

However, because the Tosa is controlled in many countries, getting hold of one can be quite difficult.

A Tosa Inu isn’t aggressive by nature, but this behavior was learned in the past.

Even so, training a Tosa from a young age is necessary to minimize any potentially negative characteristics.

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The legal control over the breed means there hasn’t been as much work with selective breeding to remove aggressive habits.

A Tosa Inu can make a good choice for a family dog, but owners should be cautious about keeping one around small children, mainly because of the breed’s size.

However, a Tosa will be happy to play with older children and form strong emotional bonds with every family member.

Similarly, Tosa Inus are generally fine around other animals, although the breed retains a strong prey instinct.

This means owners should be careful around small animals, but there shouldn’t be any problems with other dogs.

However, the breed’s dangerous reputation means that the bigger problem will likely be with other owners rather than the actual dogs.

When it comes to exercise, a Tosa will need a reasonable amount. Most importantly, they have excellent stamina, so it’s best to give them longer walks than shorter, more intense exercises.

A daily walk of at least 30 minutes is fine, but longer is better. Also, this should be supplemented with playtime for mental stimulation.

A Japanese-bred Tosa will generally be fine to live in an apartment, which is probably why their size is so small.

A larger one, however, will have a hard time living in an apartment. If you do decide to keep a Tosa in your apartment, make sure it gets more exercise and plenty of mental stimulation to keep it entertained.

Tosas are very protective of their owners and make excellent guard dogs. Their wariness of strangers doesn’t continue while out on a walk, which makes things much easier.

However, a Tosa will easily feel threatened by some actions, so owners should carefully manage the dog while out walking.

A Tosa can be left alone for longer periods, although this will be easier if it’s left with another dog.

Alternatively, try crate training to establish a routine and manage the dog’s behavior more effectively.

A Tosa that goes too long with human attention can become destructive or depressing.

Due to their Japanese origins, Tosa Inus are fine to be kept in almost any climate. Owners should be careful in hotter locations because the breed’s size can make it difficult for them to control their temperature.

A Tosa should be watched carefully during hot summer months and only exercised during the coolest parts of the day.

A Tosa Inu won’t be a particularly good choice for first-time owners because of their size and temperament.

While Tosas are generally friendly and affectionate, their owners need to be confident and experienced to manage any potentially aggressive behavior.

Also, Tosas are quite strong dogs and would easily pull away from an owner who isn’t the most confident. For this reason, first-time owners would be better looking for a smaller, easier-to-manage breed.


The Tosa Inu has a short coat that’s sleek and dense. This means, more than anything, that it needs very little grooming. Similarly, they don’t shed very much, but this is consistent throughout the year.

A Tosa won’t need to be brushed weekly; once every two weeks should be enough.

Aside from this, the odd bath will help keep their coat soft and shiny, but too frequent bathing can result in some skin conditions. Once a month is an absolute maximum for bathing a Tosa.

A Tosa’s nails grow very quickly, an unfortunate side effect of their fighting past.

Their nails will need clipping more regularly than other breeds, even if the dog gets plenty of exercise. Their nails can split easily, so it might be best to do this with a file instead of clippers.

Also, Tosas have floppy ears that must be checked every few days for wax and debris. They should be cleaned weekly to avoid infection, and their teeth should be brushed every few days to avoid dental problems.

 Common Diseases and Conditions

Unfortunately, there isn’t much information on the Tosa Inu’s health complications.

This is because of the breed’s controlled status, and even in countries like the USA, where it’s not banned, it’s only recognized as foundational stock by the American Kennel Club.

However, potential owners should know that there are many health complications associated with bigger dog breeds.

Many of these have to do with the speed at which the dog grows and can lead to bone weakness or improper development. These are avoided through proper diet and exercise.

Also, because they’re muscly, Tosas can have difficulty regulating their temperature in hot weather.

This means heatstroke can be a big problem in the breed, but this can be avoided with careful exercise planning and educating yourself on the signs of the condition.

While it isn’t necessarily a condition, potential owners should also be aware of the breed’s diet needs.

Not only do they eat a lot of food, but they also need high-protein diets and benefit from a raw diet. This can become pretty expensive and might put some people off.


The Tosa Inu was developed in the 19th century in Tosa, Japan, which is modern-day Kochi. Tosa Inu means “Tosa dog,” as Inu is Japanese for dog.

The Tosa Inu was specifically designed for fighting. Breeders started with a local dog, the Shikoku Inu, and crossbred it with several European breeds.

These included the English Mastiff, St. Bernard, the Old English Bulldog, and the German Pointer.

All of this was designed to create a larger, stronger, more powerful breed that would be much better at fighting.

The dogs’ aggressive tendencies were taught to them, although selective breeding was done to find dogs with higher aggression.

Tosa Inus were most popular in the early half of the 20th century, and while they were transported worldwide for fighting, they remained most popular in Japan. The Tosa Inu is still used there for legal dog fighting.

As previously mentioned, the Tosa Inu is restricted or completely banned in many countries because it’s considered a dangerous breed.

This puts it in the same group as dogs like the American Pit Bull and Staffordshire Bull Terrier.

However, as with these other breeds, owners are working hard to improve the Tosa’s reputation.

Tosas are currently banned or restricted in countries including the UK, Australia, New Zealand, Denmark, Malaysia, and Iceland.

In the future, this might change as the breed’s popularity increases.

Surprisingly, the Tosa Inu is legal in the USA and has been recognized by the American Kennel Club since 1997. It’s also been approved to compete in events since 2010, hopefully making a difference in the breed’s reputation and popularity. 

Did you Know?

  • The Tosa Inu almost became extinct during WW2 because of food shortages. More than anything, the Tosas became food.
  • Tosa Inus bred outside Japan look more like European Mastiff dogs. This is mainly because breeders have favored larger dogs, which meant they were crossbred with other dogs.
  • Tosa Inus are given the same social status as Sumo wrestlers in Japan. It’s not uncommon to see a Tosa dressed up in full Sumo wrestling gear!
  • The price of Tosa Inus is massively affected by their availability. They will generally cost around 2,500 USD, depending on how many breeders there are.

About the author: Driven by his lifelong passion for dogs and an insatiable curiosity about their diverse breeds, Pablo Pascua founded dogbreedsfaq.com. Through this website, he seeks to expand his knowledge and share his findings with fellow dog enthusiasts. Having owned several dogs throughout his life, Pablo’s experiences have fueled his interest in learning more about these beloved animals. His mission is to provide accurate and comprehensive information to help pet owners make informed decisions about their furry companion.