AKC Working Group


Photo copyright © Cook PhoDOGraphy. All rights reserved.

Photo copyright © Cook PhoDOGraphy. All rights reserved.

True to his name, the Bullmastiff originated through crosses between bulldogs and mastiffs, probably as early as the late eighteenth century. The breed was not officially recognized until the 1920s, however. The Bullmastiff was developed as a gamekeeper’s dog; his job was to track down, tackle, and then hold down poachers so the gamekeeper could take them into custody. The dogs were fierce and tenacious, but were trained not to bite intruders. When gamekeepers’ needs for dogs decreased, the dark brindle dogs so good for night camouflage gave way in popularity to the lighter fawn colorations. Today’s Bullmastiff has the same general look as his working ancestors, but he is generally cherished as a reliable, loyal family companion and guardian.


The Bullmastiff is a very powerful, nearly square dog that should appear to be 60% Mastiff and 40% Bulldog. It has a broad, wrinkled head and fairly short, square dark muzzle (about one third the length of the whole head). The nose is black with large nostrils. The dark, medium-sized eyes should have an alert, intelligent expression. The V-shaped, wide-set ears are pendant and dark colored. The teeth should meet in a level or slightly undershot bite. The short back is straight and level between the withers and the loin. The tapering tail is set high and reaches to the hocks. The short, smooth coat comes in brindle, fawn, or red, often with a black mask and black ears.

Key Facts

  • Height: 25 to 27 in. (male); 24 to 26 in. (female)
  • Size: Large
  • Weight: 110 to 130 lbs. (male); 100 to 120 lbs. (female)
  • Availability: Might take some effort to find
  • Talents: Tracking, watchdog, guarding, and police work


The Bullmastiff can be aggressive with other dogs, but may be OK with other pets if raised with them from puppyhood. (Note: The Bullmastiff is a more aggressive breed than the Mastiff.) Tends to drool and snore. Puppies may seem uncoordinated. Be sure to exercise this breed and not overfeed him, as he tends to put on weight. Lives about eight to ten years. Beware of hip dysplasia, tumors, bloat, and eyelid problems. Buy only from stock with OFA, PennHIP, or another national hip-dysplasia clearance. Also prone to boils on the lips. This extremely powerful dog should be trained not to pull on the leash!


An alert guard dog. Loyal and devoted, with a good-natured temperament, though he tends to be willful. Docile unless provoked; if provoked he is reputed to be fearless and protective. Needs a firm master and should be thoroughly obedience trained for safety. Be sure to socialize extensively with both people and other dogs at an early age. Despite his guard dog characteristics, the Bullmastiff is considered a loyal and affectionate breed that is relatively mellow.


  • Children: Good with children only when raised with them from puppyhood
  • Friendliness: Reserved with strangers
  • Trainability: Not easy to train
  • Independence: Moderately dependent on people
  • Dominance: High
  • Other Pets: Might be aggressive with same-sex dogs; do not trust with non-canine pets
  • Combativeness: Tends to be fairly dog-aggressive
  • Noise: Not a barker
  • Indoors: Relatively inactive indoors
  • Owner: Not recommended for novice owners


  • Grooming: A little grooming needed
  • Trimming and Stripping: No trimming or stripping needed
  • Coat: Short coat
  • Shedding: Average shedder
  • Exercise: Moderate exercise needed
  • Jogging: A poor jogging companion
  • Apartments: Will be OK in an apartment if sufficiently exercised
  • Outdoor Space: A small yard is sufficient
  • Climate: Best in cooler climates
  • Longevity: Short (under 10 years)

Useful Links

AKC® Bullmastiff Breed Standard


Bullmastiff Breed Club


Search for a Breeder


Rescue Organizations


Books about the Bullmastiff


Bullmastiff Gifts