Tosa Inu | Information & Dog Breed Facts


Tosa Inu or Japanese Mastif is an imposing, beautiful and loyal dog, of a nature reserved for foreigners but tender with its closest relatives. It is a large dog, with physical characteristics of molossoid type which can calmly exceed 60 centimeters in height at the cross.

There are few breeds of dogs that have their origin in Japan, and it is one of them, but not as well known in the world as akita inu or shiba inu. The Tosa Inu is a large dog, very impressive in terms of appearance and one of the most appreciated breeds for those looking for a dog of large proportions and unique characteristics.

Tosa Inu

“Four-legged sumo” – this is how the Tosa Inu breed is called in Japan. This name arose due to the fact that Tosa is similar in many characteristics to heavyweight sumo wrestlers. The Japanese Mastiff is bred as a fighting dog. He is heavy, large, fearless, practically insensitive to pain, has a firm, strong character.

In the modern world, dog fights are prohibited, but they are still organized illegally, and Tosa Inu often become participants and winners. In addition to the ideal fighter, the Japanese mastiff is able to be an excellent companion, bodyguard, but subject to serious training and early socialization.

The highest population of Tosa Inu is observed in Japan. In other countries of the world, they are not widely used.

Other names: Tosa Token, Tosa Ken, Tosa Dog, , Japanese Fighting Dog, and Japanese Mastiff.

If you are thinking of adopting a Tosa Inu dog, it will be essential to be properly informed about its character, the care it will need and the health problems related to the breed. It is a dog which is not adapted to any type of family, this is why its adoption must be studied correctly and carried out in a responsible manner.

Find out everything you need to know about the Tosa Inu in this ‘ Pets Feed ‘ breed sheet and find out if it’s the perfect dog for you:

Tosa Inu
Tosa Inu

Tosa Inu breed history

The origin of the Tosa Inu breed dates back to the second half of the nineteenth century. The homeland of this species is Japan. The Japanese consider these dogs to be a national treasure.

This dog was bred on the island of Shikoku, more precisely, in the province of Tosa, hence the name “Tosa Inu”.

Relatively small (weight about 21-23 kg.) Japanese Spitz dogs are the ancestors of modern Japanese mastiffs. They are very similar to the Akita Inu, their purpose was to hunt wild animals and participate in dog fights. These were leaders, local champions, who were appreciated by samurai, who raised the fighting spirit of the fighters.

But the time has come, Japan opened its borders to foreigners. Visiting Europeans began to import their war dogs into the country, which increasingly began to win in the ring of local champions. The Japanese were not satisfied with such defeats, on their territory the indigenous species of dogs should have been the winner.

For this reason, it was decided to create a new fighting breed that would surpass the Europeans and could defend the honor of the Motherland. Further, by dates, we will trace the formation, emergence and level of the population, the popularity of a new species of Japanese fighting dogs called “Tosa Inu”:

  • 1860 – the beginning of active selection work. The goal was to reduce pain sensitivity and increase combat capabilities. In the process, crossing of a pit bull, bull terrier, staffordshire was carried out. The genes of these breeds were considered the basis of the new species.
  • 1872 – breeding work on the improvement of the Japanese Mastiff does not stop. The blood of the Akita, Pit Bull, and old-style Bulldogs was mixed. As a result, the breeders were not satisfied with the small, in their opinion, dimensions of the resulting mestizos.
  • 1874 – the genes of the English mastiff are used, as a result, the new species acquires an impressive size and a voluminous head. But there are serious disadvantages: some clumsiness, loss of speed, as well as excessive aggressiveness towards people.
  • 1876 ​​- crossing with a German Pointer is carried out, his genes brought balance and reduced aggressive behavior towards humans.
  • 1924 – wanting to give the Tosa the appearance of an athlete and increase mobility, the breeders decide to cross with the Great Dane.

For several generations, work has been carried out to improve the Japanese mastiff. Inbreeding was carried out at full speed. The development of a breed standard was still in the planning stages.

As you know, during the years of the war against fascism, most large dog breeds were on the verge of extinction. The Tosa Inu population did not suffer such damage. Connoisseurs of the breed managed to take the best breeding specimens to Korea and Taiwan in time.

In some countries, the Tosa Inu is one of the prohibited dogs, they cannot be bred or kept. This breed is considered too aggressive and dangerous.

Tosa Inu
Tosa Inu

Physical characteristics of the Tosa Inu

One word that can be used to define the Tosa Inu is “immense”. It is a very large dog, but also strong and robust, with an aspect of power almost unmatched by any other breed. It is almost as tall as it is long, so it maintains perfect proportions and the muscles prepared for the action are marked all over its body.

The Tosa Inu is an animal synonymous with strength and endurance, as evidenced by the length and firmness of its legs and the depth of its chest. In addition, its head is large, with a square muzzle and of medium length, which indicates an enormous force in its bite. The nose is broad and black, and his eyes are small and very dark, with a deep and penetrating look. The ears are medium or large in size and fall on both sides of the head, and the neck is very wide and robust, creating a common image of danger and ferocity.

The back of the Tosa Inu is straight and elongated, and ends with a wide tail at its base and pointed at the tip, also very long which it generally takes at medium height. In short, it is a very well trained dog, trained to perform any activity and large enough to intimidate anyone who approaches.

Size of the Tosa Inu

The standard of Tosa Inu does not include a size or a maximum but for the dog, but a minimum height, which will be around 60 centimeters in the male and 55 centimeters in the female. From these measurements, the weight should be provided with the height, so that each specimen is athletic, slim and balanced. It is not uncommon to find copies with an average weight of between 50 and 100 kilos, but always depending on their size.


Tosa Inu
Tosa Inu

The coat of the Tosa Inu is characterized by being very short and attached to the animal’s body, which allows you to see the whole design of its musculature. It is also very dense and rough to the touch, and is generally represented in light tones, such as red, tabby or fawn.

One of the most striking features of the coat is that the muzzle changes color, where there is a black mask that can cover various extensions of its face. The great advantage of this fur is that it requires little maintenance, so it will be easy to enjoy the maximum splendor of the dog without having to devote a lot of time and effort to take care of it.

Character of the Tosa Inu

According to the official standard, the Tosa Inu has a patient, daring and valuable temperament. It is a dog very faithful to the family, very sure of itself and its physical abilities. It is usually a little shy and reserved for those who do not know, who will hardly pay attention, but very devoted to those who treat it with affection and tenderness.

The relationship with young children is generally excellent. The Tosa  Inu has a natural instinct of protection and a calm and relaxed temperament inside the house, which marries perfectly with the little ones, and will endure their pranks and their ear prints. However, the Tosa Inu is a big dog that can hurt without wanting to run or play, for this reason it is strongly recommended to always monitor the game and properly educate the children to understand how they should treat this noble dog.

With other dogs, the Tosa Inu can get along as long as it is properly trained as a puppy, however, it is important to monitor the reaction it has to reactive dogs and it is that the Tosa Inu is a dog of great value and courage who will not hesitate to protect those it considers as its life partners.

It is strongly recommended that responsible adoption of Tosa Inu be done by an experienced and knowledgeable breed. If we are not used to training or keeping big dogs, it will be better to opt for other breeds. Similarly, if behavioral problems arise, it will be essential to contact a suitable professional dog trainerto help us and guide us in its education and care.

Let’s not forget that because of its great physical strength, this dog will need someone who can control it in the event of an emergency. Regular wearing of traction harness and obedience at work will be fundamental factors if you do not have enough physical ability. Keep this in mind.

Tosa Inu
Tosa Inu

Tosa Inu Health

The average life span of a Japanese mastiff is 9-12 years. The health of a tosa inu depends a lot on the owner. The fact is that the representatives of the breed are extremely hardy, they have a very high pain threshold. Therefore, it is difficult to determine whether the pet is suffering from pain, whether it is tormented by any health problems.

The owner must carefully monitor the condition and behavior of the dog. If the animal has lost its appetite, has become inactive, its coat has faded, then it is time to visit the veterinary clinic for examination and testing, since the listed symptoms usually signal some kind of disease. In general, it is recommended that such inspections be carried out at least once a year.

In addition, deworming and vaccination should be carried out on time. It is important to treat the dog with drugs for skin parasites, especially in the spring and summer.

Although nature has awarded the Tosa Inu with good health and strong immunity, the predisposition of the breed to certain diseases is observed:

  • Dysplasia of the elbow, hip joint – at first the dog is limping, does not allow to touch itself, as the pains are getting stronger. Then the front or hind limbs are taken away from her.
  • Allergic dermatitis – an undesirable reaction to detergents or food is possible.
  • Diseases of the cardiovascular system.
  • Ear infections – due to the peculiar structure of the ears, Tosa Inu often have infectious diseases. It is recommended to treat the auricles with a special solution.
Tosa Inu puppies
Tosa Inu puppies


The Tosa Inu is a dog that will need 2 to 3 daily walks that will allow it to interact with other animals, exercise, relax and enjoy mental stimulation. A good exercise that combines stimulation and relaxation is sowing, a very simple activity to perform.

It would be ideal if Tosa Inu could live in a spacious house, and even a house with a garden. However, the Tosa Inu can adapt to living in an apartment if it sees enough care and exercise.

Basic care

The mastiff is not very suitable for keeping in a cramped apartment. He needs space, fresh air and, most importantly, great physical activity. Therefore, the best option for keeping the Tosa Inu is the countryside, a country house with a large garden plot.

Tosa-ken does not apply to sedentary dogs. He is active, additional loads are recommended for the development of his muscles, but only from the age of two.

Walking should not be limited to a leisurely walk along the alley. Plan your walk so that the dog has the opportunity to play active games, run and jump. Please note that each walk lasts at least 2 hours.

For enclosure living, an insulated booth is needed. It is not recommended to keep such a dog on a chain, from such a restriction of freedom its character will deteriorate.

With regards to caring for the Tosa Inu, then all the necessary procedures are easily performed, if only you teach the pet to them from puppyhood. The list of procedures is set out below:

  • Comb the wool 2-3 times during the week. It is better to use a rubber brush. Furminator is considered indispensable during molting.
  • Bathing is rarely required, about 1-2 times a year or when absolutely necessary. In summer, it is advisable to find an opportunity to bathe the mastiff in a natural reservoir.
  • Ears and eyes should be examined regularly for signs of excessive discharge, inflammation, or injury. The auricles should be cleaned weekly using the special products recommended by your veterinarian.
  • Skin folds on the face and neck must be cleaned with a damp piece of natural cloth. This procedure is necessary to avoid diaper rash. Pay special attention to the skin in the summer, when it is hot.
  • The claws are trimmed as they grow back.

It is recommended to select proper nutrition for representatives of the Tosa Inu breed together with a veterinarian. For such athletic, energetic and large dogs, a diet with a set of the required amount of vitamins, minerals, trace elements is being developed.

In order for the Tosa Inu to develop the skeleton correctly, it is important to buy special additives, gelatin.

Tosa Inu dogs
Tosa Inu dogs

IMPORTANT! Remember that Tosa Inu is a dog considered potentially dangerous in several countries. Before considering the adoption of this dog, you should consult the applicable laws and regulations of your country.

Training and education

From an early age, it is necessary to acquaint the Tosa Inu with the world around, with people, with animals. Only with early socialization, training will you be able to raise an adequate Japanese mastiff, who will obey you and obey commands without question. These rules are especially important to follow if you keep a dog.

During upbringing, training, it is strictly forbidden to use physical punishment, insults. Prohibitions and censures should be expressed in a different form, firmly and persistently, but not rudely.

Guarding, sentry instincts are present in mastiffs from birth, so you should not engage in the development of these qualities. It is important to pay attention to the dog’s adequate response to people and animals. The level of aggression must be controlled.

Be sure to take training courses with the Tosa Inu. If you can work out simple, initial commands with a pet at home, then it is recommended to go through more complex science under the guidance of an experienced dog handler.

Tosa Inu puppy
Tosa Inu puppy

How to choose Tosa inu puppies

Although the Tosa Inu is not considered a popular breed, dogs still continue to suffer from commercial breeding. Unscrupulous sellers abuse inbreeding (closely related crossbreeding) and mating with doubtful pedigree producers, which affects the quality of litters. The harsh culling of unhealthy Tosa Inu puppies, which takes place in Japan, is not held in high esteem by domestic breeders, so even defective individuals are put into sale, which subsequently create problems for the owners. To avoid this kind of deception, there are some general rules that will help you choose an honest breeder and relatively healthy tosa inu puppies.

No nurseries! The dogs must have enough space to move and play. In addition, animals living in cramped and poorly ventilated rooms are always more likely to catch an infection.

Study the pedigrees of the litter breeders. It is better if they are descendants of Japanese lines. In addition, a Tosa Inu male and a female should not be littermates, since offspring from such parents is a big lottery.

Give the Tosa Inu puppies a courage test by suddenly clapping your hands over their heads. Correct Tosa Inu will not rush off, sparkling with heels, but will only listen to a sudden threat.

Look at how the puppy moves for any stiffness and limp that are common with joint dysplasia. Be sure to ask them to show the results of a survey of offspring producers for the presence of this disease.

Tosa Inu price

Since acquiring Tosa Inu in Japan is still incredibly difficult, most compatriots continue to buy individuals from American and European lines. At the same time, it is important to understand that European and American individuals will be like their Japanese tribesmen only in the exterior plan – in order to get a sustained character and combat training, the Tosa Inu must be born in the Land of the Rising Sun, from Asian producers. As for the cost, the standard price tag for pet-class Japanese Tosa Inu in ranges from 1000$ to 2000$.

Facts about Tosa Inu

  • There are two types of lines linked to the dog Tosa Inu, on the one hand that bred in his country of origin, Japan, and on the other hand that of the rest of the world. Although it is the same breed, the two varieties have an important difference, it is that the Japanese variety is generally much smaller than the foreign varieties. On average, a Tosa Inu dog bred in Japan will weigh between 25 and 55 kilos, but a specimen bred outside of this country will weigh between 60 and 100 kilos.
  • Being considered a potentially dangerous dog in various countries, including several European countries, not everyone has access to a puppy of this breed. In order to acquire a copy of the Tosa Inu, it will be necessary to have beforehand an appropriate license and insurance, it is therefore preferable to go to the legislation of the country in particular to know the steps to follow.
  • During the Second World War, keeping the Japanese Mastiff was punishable by death.
  • The Tosa Inu is the only Molossian breed in Japan.
  • In the United States, Tosa Inu became famous as a participant in weight pulling. The champion who took the weight of 1585 kg. Is a representative of the specified species.
  • The Japanese Mastiff’s career as a fighting dog is similar to that of a sumo wrestler. Fighter dogs compete in different weight categories and have different ranks (maegasira, komusubi, sekivake, ozeki, yokozuna, yuseken).
  • American studies have shown that in Japan purebred Tosa are used as babysitters for children, which is extremely surprising, because these fighting dogs are on the list of the most dangerous breeds with an increased level of aggression.
  • Specially trained fighting Japanese mastiffs belonging to samurai are called “shadow of the samurai”. Such dogs literally always follow their master’s heels.
  • You already know the responsibilities and the process you will have to follow to get a Tosa Inu puppy. If you think this breed is best for you, it will certainly be worth it. You should also contact a breeder specializing in the breed as soon as possible, as that way you will have all the health guarantees regarding your new best friend and you will be able to receive first-hand information on everything related to Tosa Inu.
Japanese Mastiff

Tosa Inu Dog Breed Highlights

An insecure, unbalanced person cannot be the master of Tosa-inu. So, if you liked the indicated breed of dogs, think carefully about whether you can provide it with decent maintenance and a sufficient level of education.

The main pros and cons of the breed are outlined in the list below.


  1. Devotion.
  2. Endurance, strength and fearlessness.
  3. Easy care.
  4. Good health.
  5. The innate instinct of a guard, watchman.


  1. Not suitable for apartment maintenance.
  2. Requires daily strenuous physical activity.
  3. Increased level of aggression, needs control.
  4. Tendency to dominate.