Bullmastiff Guide: Size, Temperament, Lifespan and Rescue Adoption
Overview: the full breed Bullmastiff
The AKC places the Bullmastiff in the Working Group and lists England as its origin. UKC describes a powerfully built, alert and fearless dog that is still docile in manner. The coat is short, and the standard allows red, fawn or brindle colors.
History
Gamekeepers on large English estates wanted a courageous dog that could catch and subdue poachers without mauling them, and a mastiff and bulldog cross filled that role. The breed was so good at this work that it was nicknamed the gamekeeper's night dog.
How big do Bullmastiffs get? Size and weight
For bullmastiff size, AKC lists males at 25 to 27 inches and females at 24 to 26 inches. For bullmastiff weight, AKC lists males at 110 to 130 pounds and females at 100 to 120 pounds. UKC gives the same height and weight ranges for each sex. AKC places the breed in its XLarge size category.
Bullmastiff temperament and personality
AKC describes the Bullmastiff's temperament as loyal, affectionate and brave. VCA describes the breed as often calm and well-mannered in the house. VCA notes that it tends to be suspicious of strangers, so early socialization is essential. It is generally good with children but may be overly protective of them around strangers, and VCA says dogs and children should be supervised.
Exercise needs
VCA says the breed needs daily exercise such as a moderate walk or short jog. VCA adds that it prefers cold weather to warm.
Grooming
VCA recommends only occasional brushing to remove dead hair, and notes that deep facial wrinkles may need cleaning and drying. AKC rates grooming frequency low and shedding and drooling in the middle of its scale.
Training
VCA says the Bullmastiff tends to be stubborn and rebels against forceful methods. It does best with a firm owner who combines reward-based training with good control and leadership. Obedience training is valuable for control and for the mental exercise it provides.
How long do Bullmastiffs live? Lifespan and health
AKC gives a general bullmastiff life expectancy of 7 to 9 years, which answers how long Bullmastiff dogs live. VCA says Bullmastiffs tend to stay in good weight or be slightly overweight, so adults may need restricted calories if they gain too much. VCA also advises feeding puppies a large-breed growth food, which may decrease the incidence or severity of hip dysplasia in adults.
Bullmastiff rescue adoption: what to consider
Anyone considering bullmastiff rescue should be prepared for a dog that often needs early socialization and may be wary of strangers. A firm owner who uses reward-based training and good control tends to suit the breed.
AKC breed facts
These are the American Kennel Club’s general facts and 1 to 5 ratings for the Bullmastiff as a breed. General tendencies don’t establish any one dog’s ancestry, personality or health; ask the listing organization about the dog you are considering.
- AKC group
- Working Group
- AKC recognition year
- 1934
- Height (AKC published)
- 25-27 inches (male), 24-26 inches (female)
- Weight (AKC published)
- 110-130 pounds (male), 100-120 pounds (female)
- General life expectancy
- 7-9 years
- AKC size category
- XLarge
AKC general breed ratings (1 to 5)
- Energy: 4 of 5
- Mental enrichment: 4 of 5
- Trainability: 4 of 5
- Grooming frequency: 1 of 5
- Shedding: 3 of 5
- Vocalization: 1 of 5
- Drooling: 3 of 5
- Adaptability: 3 of 5
- Playfulness: 3 of 5
- Watchful or protective tendency: 5 of 5
- Affection toward family: 4 of 5
- Openness toward strangers: 3 of 5
- AKC child compatibility rating: 3 of 5
- AKC dog compatibility rating: 3 of 5
Health screenings AKC lists for the breed
Breeding evaluations AKC names for the breed; they are not a diagnosis or a testing plan for any one dog.
- Hip Evaluation
- Elbow Evaluation
- Cardiac Exam
- Ophthalmologist Evaluation
- Thyroid Evaluation
Source: American Kennel Club breed profile (opens in a new tab), retrieved November 4, 2026 (snapshot akc-2026-11-04).
Written by Lily's Second Chance with AI assistance from the sources listed under References. Facts were checked automatically against those sources on November 7, 2026.
References
- Breed Standards : Bullmastiff | United Kennel Club (UKC) (opens in a new tab), United Kennel Club, checked November 7, 2026
- Bullmastiff | VCA Animal Hospitals (opens in a new tab), VCA Animal Hospitals, checked November 7, 2026
- Bullmastiff - AKC breed profile (snapshot akc-2026-11-04) (opens in a new tab), American Kennel Club, checked November 4, 2026
