Essentially a popular companion dog, the Shiba still has a predatory instinct as it was bred as a hunting dog. The dogs do not take kindly to provocation and can show aggression, but above all, when expressing emotion, these dogs emit what is labeled as the “Shiba scream.” This high pitched scream can ward off unwanted guests and can also serve as a strong warning sign for mishandling.
The Shiba is Japanese (it is a Japanese breed!) for Brushwood, which is a type of shrub or bush that turns red in the fall. Many people believe that is what was kept in mind when naming the dog. On the other hand, in Nagano, an ancient Japanese dialect, Shiba also means small. Either way, this “Little Brushwood Dog” packs a punch.
56. Great Pyrenees
Do not be fooled by the zen-like attitude of the Great Pyrenees. These dogs seem very calm but can swiftly shift into action when threatened. Their immense power makes them a deadly opponent, especially with their height of over 32 inches at the shoulder and weight of more than 100 pounds.
The Great Pyrenees is related to many other large LGDs such as the Newfoundland dog, the St. Bernard and the Polish Tatra Sheepdog.
57. English Mastiff
This English Mastiff has been compared to the Bull Dog. Both these dogs can be just as ferocious, both can enter into combat with the temper and eagerness to attack, but while the Bull Dog, in a blind rage, might bite the hand of his own master, the English Mastiff can distinguish perfectly between friend and foe.
These back-masked giants are massive and stand at about 30 inches. The rectangular body has heavy muscles and it's broad and large head can be rather startling when staring at straight on.
59. Boston Terrier
While the Boston Terrier is essentially a playful dog, it is still highly protective. It is that "eager to please" approach that makes them actually rather aggressive and territorial when needed. Bred initially for fighting, these dogs only later became companion dogs.
Early training is essential as they can very quickly get out of hand. Their edginess can turn into a nasty aggressiveness if not disciplined properly.
60. Bernese Mountain Dog
These working dogs were brought to Switzerland about 2000 years ago by the Romans for the purpose of guarding large mountainous terrain, so it seems only natural that these dogs should have quite a bit of fight in them.
Like any worker dog, this breeds is fiercely loyal and will attack intruders with zero hesitation. Best for farms and larger suburban areas, these dogs need a lot of roaming area.