In their native South Africa, these powerful farm dogs fend off fierce predators like leopards. Because of their strength and dominance, the AKC recommends prior experience owning large breeds before adopting a Boerboel.
According to the AKC, Tosa dogs (Japanese Mastiff) used to be bred for fighting but are now used as watchdogs, a position perfect for their calm, patient and vigilant personalities.
Known as the friendly giant of the Swiss Alps, according to the AKC, Saint Bernards are gentle and tolerant, especially with children. They don't fawn over strangers and can be used as a watchdog.
Gentle and loving, this breed is excellent for kids. According to the AKC, Great Danes are alert guards, but not overly aggressive. They're moderately intelligent, but highly stubborn and not easily trained.
Affectionate might be an understatement — Leos want to be with their families at all times! DogTime states the breed is a mix of some of the other largest dogs
With a droopy face and a tendency to drool, Mastinos may look a little dopey (just think of Hagrid's dog Fang in the Harry Potter movies), but they're really designed to be protective guard dogs.
Despite the misleading name, Anatolians are bred as guard dogs, not herders. They can be protective and territorial, but still calm and affectionate with their families, according to PetMD.
Brave, affectionate, and loyal, Bullmastiff dogs can be both great family members and protectors. They're especially willing to please and, despite their large stature, don't require much exercise.