The Shiba Inu as a very interesting history tied to dog fighting as it is member of the six main breeds in Japan. It carries the blood of a champion since it shares its lineage with the Tosa Inu. There exists the Shiba Inu-type Tosa and the fighting Tosa Inu. Dog fighting is of course illegal and considered immoral today, but in ancient Japan it was an encouraged and popular sport.
The Tosa Inu became popular in Japan during the samurai period. Warriors would come home after a war had ended with no outlet for the aggression and skill they had instilled in them. Thus they began dog fighting as a barbaric stress reliever and pastime. The Shiba Inu's close kin, the Tosa Inu became a popular dog to fight because of its intelligence and courage displayed during fights.
A number of dogs have been introduced to the bloodline of the Tosa Inu: the Bulldog Bull Terrier, the Mastiff, and the Great Dane. These dogs were crossbred for their size while even pointers, were integrated into the breed so as to make it more obedient. Thus, the Tosa Inu is the exact opposite of the Shiba Inu. It is an enormous dog while the Shiba Inu is not.
The Tosa Inu is dissimilar to the Shiba Inu in further ways. It has a massive, wrinkled head, with drooping ears, which is nothing like the perky ears and smooth visage of a Shiba Inu. The Tosa Inu eyes are small and not slanted. He is extremely muscular and while a Shiba Inu can be so too, the Shiba Inu is not so big-boned. And the Shiba Inu can come in a variety of colors while the Tosa Inu is usually bred to be a red color. And Tosa Inu dogs have the patience that the Shiba Inu does not have to be therapy and rescue dogs.
Much like its close bloodline relative, the Tosa Inu is expensive, with prices ranging from a thousand dollars and up. And that is not including care and grooming costs. Also, where a Shiba Inu can live is not the same for a Tosa Inu. Because of their girth, Tosa Inus have to live in places with a lot of space.
Then Shiba Inu and Tosa Inu's are extremely different yet still somehow manage to be alike. They are both rambunctious and quite intelligent. They both are incredibly independent minded which takes a lot of training to help subside. Furthermore, just as the Shiba Inu is defensive, so is the Tosa Inu. Much like the Shiba Inu, the Tosa Inu has to be well-disciplined and socialized from when he is a puppy if an owner wants to have any type of control over him. The Toba Inu and Shiba Inu are both somewhat aggressive towards strangers, but when it comes to their owners they can be both be fiercely loyal companions.