Bullmastiffs can weigh up to 130 pounds when full grown. Males can grow up to 27 inches tall, while females can grow up to 26 inches tall. They are generally red, brindle-brown or fawn colored.
In England, bullmastiffs were bred to guard large estates and keep poachers out of game preserves. Although large and muscular, these dogs are even tempered, gentle dogs with their families. They can be protective when pressed, but their massive size and presence is generally enough to deter interlopers. Instead of biting and mauling poachers and intruders, bullmastiffs are more likely to pin them down and wait until their owners show up. They are intelligent dogs that make good family companions when treated well and given adequate amounts of exercise.