The Bullmastiff is a large-sized breed of domestic dog, with a solid build and a short muzzle. The breed's bloodlines are drawn from the English Mastiff and the extinct Old English Bulldog.
The bullmastiff has a large, wrinkled head and a fairly short, square muzzle. The nose is black and the eyes are dark hazel. The ears are v-shaped and hanging downward. The tail is set high on the rear end and reaches to the dog's hocks. The bullmastiff's body is large, powerful, and square looking. The coat hair is short and easy to maintain; coat colors could be fawn, reddish-brown or brindle. A bullmastiff ranges in height from 24 to 27 inches and weighs between 100 to 130 pounds.
The bullmastiff was developed during the mid-19th century by British gamekeepers to protect country estates from poachers. By mating the larger mastiff with the bulldog, breeders were able to develop a powerfully built but active dog that could cover run fast, knock a poacher down to the ground, and hold him hostage until the gamekeeper arrived to apprehend the intruder. The breed was recognized by the American Kennel Club (AKC) in 1933.
Bullmastiffs are gentle and affectionate with family members. Their generally calm, easy-going natures make them good dogs for families with children who can treat the dog with respect. However, the bullmastiff's easy attitude with family members is likely to change with strangers. These dogs tend to be quite suspicious of people outside the family.
For all its family-oriented loyalty, the bullmastiff can be an independent-minded dog, which can make training a challenge. It also may be less tolerant of a family's pets than of its human members.
Sources: http://sequin-pillow.com/site/1zzmc8.php?tr=4-month-old-bullmastiff-weight
https://www.hillspet.com/dog-care/dog-breeds/bullmastiff
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