The Tosa is a stately, massive dog that’s athletic and surprisingly agile. The head is large, with a broad skull, a fairly abrupt stop, and a moderately long, squared-off muzzle. The jaws are very powerful. The skin at the neck forms a dewlap. The ears are fairly small and pendant. The eyes are small, dark, and almond-shaped, with a dignified expression. The long tail is very thick at the root, then tapers to a point. The large height and weight range in the Tosa breed is due to their background in dog fighting; they are grouped into light, middle, and heavyweight classes. The average weights for U.S. Tosas are: males—120 to 170 lbs. and females—90 to 140 lbs. The coat is short, dense, and harsh. The preferred color is solid red, but black, fawn, and brindle are permitted.


The Tosa, often referred to as the "Sumo wrestler of the dog world," has been bred for hundreds of years in Japan. The breed excels at Japanese-style dog fighting. The Tosa we recognize today was developed in the late 1800s when the best of the Japanese Tosas were crossed with newly imported European breeds (the Great Dane, Mastiff, Bulldog, and St. Bernard) to increase its size. The result was a powerful, agile, and athletic Mastiff-type dog. In Japan, the Tosa (also called the Tosa-inu or Tosa-ken) is considered a national treasure. The Tosa is a rare breed, even in his native land, and has only recently been introduced to the United States. This massive dog makes a fine guardian and watchdog. He also can be a good companion if properly socialized and trained.

Key Facts:



Brave, fearless, and bold. Very attuned to his master's wishes. Protective and loyal. Exceptionally quiet, calm, and patient. Highly intelligent; does not need repetitious training. The sheer size of the Tosa and his deep bark are effective deterrents. Wary and protective with strangers, but will accept newcomers if properly introduced. Both males and females make excellent home and family protectors and companions. Tosas show remarkable acceptance of children and do not snap or bite from fear or pain. However, due to the Tosa's size, he should not be left with children unsupervised. The owner must learn to control the Tosa, as the breed is too large and strong to be unmannerly. Not a good candidate for dog parks, or anywhere he can mingle and fight with other dogs. Good with other dogs and pets only when raised with them from puppyhood, and even then, this dog should not be left unsupervised. Not recommended in a home with another dog of the same sex, size, and temperament.