The Bullmastiff is a confident and fearless breed who is relatively quiet both inside and out. But if a warning bark is issued from this first class watchdog, any intruder, whether animal or human, should take the chance to retreat. Bullmastiffs, originally bred to protect against poachers, will be only too happy to back up the bark with their top tier guard dog ability. With family they are quite loving, sometimes considering themselves a lap dog. With proper socialization and training, they make quite good companions for children but, Bullmastiffs are too dedicated to serving as a guardian to also be a playmate. They usually get along with other animals they have been raised with, including cats, but may be testy with same sexed dogs. Bullmastiffs remain puppies until the age of two or three. While puppies they are rambunctious. Bred for short bursts of speed and power, despite their size, they need no more exercise than an average dog making them relatively easy keepers. Some drool; most snore.

The Bullmastiff is among the largest dogs. His short shiny coat needs little grooming. Though his shedding is no worse than average, a weekly brushing will reduce the hair lost inside. Their coats are colored either fawn, red or brindle with a black mask. A small white mark is acceptable but only on his chest. A male dog stands 25″ to 27″ at the withers and weighs up to 130 pounds; females stand 24″ to 26″ at the withers and weigh up to 120 pounds. They do reasonably well in cold temperatures but should be protected from heat above 80° F.

Like any large dog that is territorial, socialization is absolutely imperative to help the dog develop the ability to determine friend from foe. To maintain control of a dog this size, basic obedience training is also required. But Bullmastiffs are not easily trained; they are stubborn and want to do things their own way. As they mature they will test family members to see who they can dominate. However, they will respond to early, firm, consistent obedience training from a firm trainer who demonstrates leadership. The breed is not recommended for first-time owners or those who have little time to give their dog.