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Tosa Inu Breed Information: Facts, Traits, Pictures & More


Last Updated: August 30, 2023 | 8 min read | Leave a Comment

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The Tosa, pronounced “toe-sa,” is the largest dog breed from Japan. They also go by several other names, including Tosa, Tosa Ken, Tosa Dog, Tosa Token, the Japanese Fighting Dog, and the Japanese Mastiff. But whatever you know them as, they are calm and patient watchdogs, a true gentle giant when everything is running smoothly. But they are also vigilant and fearless, and they are an intruder’s worst nightmare.

They are sweet and affectionate with their family, but they aren’t sociable with anyone else. And most Tosa do not get on well with other dogs, so visits to the dog park are off the table. But if you’re looking for an affectionate watchdog who’s tranquil at home, you can’t get much better than this pup. However, you must be an experienced dog owner and be prepared for lifelong training because it can be challenging.

Tosa are giant dogs that weigh up to 200 pounds, so they need plenty of room to play and shake their large tail. Their backyard must be secure, and they should always be on a leash in public. Thankfully, their grooming needs are simple, and they don’t need too much exercise like other breeds. Want to find out if you and the Tosa Inu make a good match?


Tosa Inu in fighting ring with traditional Japanese robe
Tosas have a long history of dog fighting.

The Japanese Tosa originates from 14th century Japan. When Commodore Matthew Perry arrived on the island in 1854 with his naval force, breeders started to mix their fighting Shikoku dogs with these newly arrived foreign dog breeds. It is believed that Bulldogs, Mastiffs, German Pointers, and Great Danes feature in their makeup, and some accounts also suggest Bull Terriers and Saint Bernards were used too.

The Tosa Inu originates from the Tosa Province, hence their name. The area is now the Kochi Prefecture, the southwestern part of Shikoku Island. They are relatively popular in Japan, although their large size and dominant personality make them less suited to many family homes than other Japanese dog breeds. Tosas are a banned or restricted breed in many countries, including Australia, United Arab Emirates, and the United Kingdom. Unfortunately, dog fighting is still legal in many parts of Japan, and most fighting dogs are Tosas.

Tosas are the canine equivalent of Sumo wrestlers and are ceremoniously honored in full dress. The Tosa is a rare dog in America and across the rest of the world. They are currently in the American Kennel Club’s (AKC) Foundation Stock service group, which allows breeders of rare breeds to continue to work towards full AKC recognition and maintain a reliable breed record. Currently, they are only allowed to take part in Companion Events.


Tosa Inu growing in the grass
Their size and appearance can discourage intruders, making them excellent watchdogs.

The Tosa is a relatively tranquil pup with a calm demeanor, but they are always on the watch for trouble, ready to protect their family. Their watchful and protective nature typically makes them wary of other dogs and might act aggressively against them. For this reason, Tosas are best as the only animal in the home.

Tosas are affectionate with their family, enjoying a cuddle on the sofa or sitting by your feet to feel contact with you. It would be best to introduce your Tosa to visitors and strangers, showing them your approval. But don’t expect them to be overly pleased to see anyone outside the family. They are aloof with strangers and sit on the sidelines, always keeping one eye on their people. This is fantastic for most families looking for an obedient and calm watchdog, but not ideal if you are looking for a social and playfully silly pup.

Size & Appearance

Tosa Inu standing outside in the grass
Tosas have a stately manner, with a square head and muzzle, with a meaty square nose.

The Tosa is a giant dog breed that weighs between 100 and 200 pounds and measures between 21.5 and 23.5 inches tall. Males are usually larger and taller than females, although both sexes are impressively muscular and stocky. Their ears hang almost to their jawline, and their long, sweeping tail is thick at the root and strong, tapering towards the tip. Watch yourself around these dogs, as a tail whip to the leg can be painful.

The Tosa breed standard outlines all of the appearance guidelines. This is important if you intend to show your Tosa in the conformation ring in the future. But if they are just a family pet, it doesn’t matter if your Tosa is slightly smaller, larger, or a little different from the norm Tosa appearance. All that matters is that they are healthy and behaviorally sound. In Japan, Tosas usually only weigh between 80 and 130 pounds. And you often see them in full ceremonial regalia, as they are one of Japan’s national treasures.

Coat & Colors

The Tosa has a smooth and dense double coat that is hard to the touch. According to the AKC, there are five coat colors, which are red, apricot, fawn, black, and brindle. All Tosas are allowed slight white markings on their chest and feet. Many Tosas have darker-colored ears, tail tips, and black coloring around their muzzle and eyes. And this is why many of them are often confused for Mastiffs or Boerboels. Their eyes are usually dark brown, and their nails are almost black.

Exercise & Living Conditions

Tosa Inu running in a dog park with owner
A bored or restless Tosa can be incredibly destructive.

Tosas are a naturally calm breed and do not need overly energetic exercise sessions. Instead, they only need between 45 and 60 minutes of relaxed exercise daily to keep them healthy and happy. If you’re looking for an energetic and tireless hiking partner, this is not the best breed for you. Instead, think about leisurely walks around the neighborhood and run and have a fun time in the backyard. They need lots of interactive playtime or access to tough dog toys to keep them mentally stimulated.

The Tosa needs a large home with access to a secure backyard. Fences should be high and tough just in case they manage to escape chasing something or someone away. They can live with dog-savvy children who respect their need for space and know their vast size and swinging tail. The Tosa is a territorial dog not suitable for multi-pet homes, particularly other dogs. Although some Tosas get along fine with other dogs, their natural instinct is to feel threatened.


Tosa Inu face up close sitting on a leash
The Tosa is trainable and obedient.

This breed is self-willed and can be incredibly stubborn if they feel their owner isn’t up to leading them. So, if you are considering welcoming a Tosa into your home, you must be experienced and committed to lifelong training. Training a Tosa is no easy feat, but they are wonderfully obedient and loyal doggos when you crack it. You also need to be physically able to handle this large breed.

Tosas must be socialized well as a puppy. Introduce them to as many new people, sights, sounds, and experiences as possible. This also includes grooming too. Not only does this increase their confidence and reduce their anxiety, but it can make your life with them so much easier. Because if a strong-willed 200-pound pooch doesn’t want to do something, you can bet they won’t do it.

Tosas should always be on a leash in a public place. This is why leash training your Tosa during puppyhood is a handy tool for later life, especially considering their strength. An adult Tosa can easily pull their owner over if not trained to walk on a leash well. Tosas do not respond well to harsh training methods, so please keep training positive and enjoyable.


Tosa Inu standing outside in a field
All dog breeds are predisposed to certain inheritable conditions.

Tosas are very healthy dogs with a life expectancy of 10 to 12 years, a great life expectancy for such a large dog. There aren’t many concerns in the Tosa bloodline, but here are the two most common to make yourself aware of.

Gastric Dilation-Volvulus

Gastric Dilation-Volvulus (GDV) is more commonly known as bloat. It is a life-threatening condition that affects many large, deep-chested breeds like the Tosa. It usually occurs after eating a large meal immediately before or after exercise, although it can occur at any time. The stomach fills with air, twists, and restricts blood flow to other organs, leading to shock and quick death.

Hip Dysplasia

This developmental condition occurs when the hip joint does not form properly, leading to excess wear and tear and painful arthritis in later life. It occurs mainly in larger dog breeds, and asking your breeder for hip certificates is essential. To reduce the risks of hip dysplasia, be sure to feed your Tosa puppy food that is specifically for large-breed puppies. And limit highly impactive exercise when they are developing.


The Tosa Inu is a giant dog breed with a large appetite. How much they eat depends on a wide variety of factors, including their age, size, activity levels, food type, and more. There are a few essential things to remember when feeding your Tosa. Firstly, they need an age-appropriate diet, which is particularly important during puppyhood. A diet specifically designed for large or giant breed puppies helps steady the growth rate, reducing the chances of hip dysplasia.

Secondly, it must be a high-quality diet that meets their nutritional needs. Look for the Association of American Feed Control Officials (AAFCO) seal of approval. Kibble is a budget-friendly and simple way to feed dogs. A fresh subscription diet is convenient, tasty, and uses the best ingredients. Next, feed them smaller meals throughout the day rather than one large meal. And avoid feeding time close to activity to prevent bloat. And lastly, be aware of the correct portion size for your dog. Tosas are relatively low-energy dogs which means they are prone to weight gain, which can cause further strain on their joints.


The grooming needs of a Tosa dog are simple. They have a short double coat that only needs brushing weekly to keep them looking their best. They shed moderately throughout the year, like most dogs. Remember to take care of their dental hygiene by brushing their teeth several times a week.

The only additional grooming task you need to know is that Tosas have hard, quick-growing nails, so you must invest in a nail clipper or grinder. Otherwise, they might split, crack, and lead to really sore pads. Alternatively, most groomers offer nail-clipping services. Establishing a grooming regime early is essential, especially with large, powerful dogs who might resist this regime when they are old enough. Brushing a 200-pound dog’s teeth or clipping their nails when they are afraid is a near-impossible task.

Breeders & Puppy Costs

Tosa Inu puppy outside
Finding a Tosa in the U.S. might be a challenge, given their rareness.

The Tosa is a rare dog breed in America, and there aren’t many Tosa breeders. Responsible breeders screen for hip dysplasia and allow you to meet the puppy and at least one parent. Good breeders look after their pups by providing medical care and regular socialization from an early age. A great place to start your search for a Tosa breeder is the Tosa Inu Club of North America‘s Facebook page. Here you can find details of breeders, but please remember to research the breeder you want to work with.

The average price of a Tosa puppy is usually between $1,700 and $2,500. But well-bred pups from responsible breeders or litters from award-winning parents will likely be more than this. Remember that they are a giant dog breed, meaning everything they need will be on the expensive end of the cost scale.

Rescues & Shelters

It is highly unlikely to find a Tosa Inu in rescue shelters. At the time of writing, the only dependable national rescue websites with Tosa Inu listed as a search option are PetCurious and PetFinder. Other popular rescue websites we usually recommend do not list Tosas as a searchable breed. That’s how rare they are. If you are lucky enough to find a Tosa needing their forever home, expect the rescue fee to be higher than other dog breeds.

As A Family Pet

  • Tosa Inu are highly watchful, territorial, and protective dogs.
  • They are giant dog breeds that weigh between 100 and 200 pounds.
  • Tosas need lifelong training and an experienced dog owner to get the best out of them.
  • They can be independent and strong-willed but obedient when trained well.
  • Tosas are affectionate with their close family but aloof with strangers.
  • These dogs are low to mid-energy that prefer leisurely walks over vigorous ones.
  • Tosas can be good with dog-savvy kids but don’t mix well with other dogs or pets.
  • You should leash train them from an early age.
  • Their grooming regime is simple.
  • This breed is not suitable for most families.
  • They are very rare in America.

Final Thoughts

The Tosa Inu is a rare dog breed in America and the rest of the world. Their dog fighting history has earned them an unfair reputation as vicious dogs. And sadly, in some countries, such as Japan, they are still used for dog fighting today. However, responsible breeders breed Tosas for their calm, gentle, and watchful personalities. They are naturally territorial and strong-willed, so they aren’t suited to every family. But if you think you make a good match with them, research a responsible breeder and meet up with them to discuss what being a Tosa Inu owner is like.

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