Bullmastiff
鬥牛獒犬
Updated 2026-09-09
At a glance
The Bullmastiff is the gamekeeper's night dog — a large, muscular guardian created from Bulldog and Mastiff crosses to knock down and hold poachers without mauling them. Fearless at work and docile with its own people, it is a quiet, low-barking family companion that needs early training and socialisation, secure fencing and only moderate exercise. Its lifespan is short and the breed is prone to cancer, bloat and joint problems.
Facts
| Size | Large |
|---|---|
| Height | 61–69cm |
| Weight | 45–59kg |
| Life expectancy | 7–9years |
| Breed group | AKC: working FCI: 2 |
| Role | Guardian |
| Coat | Short coat |
| Shedding | 3/ 5 |
| Exercise | 60–150min/day |
| Can be left alone | up to 4 hours |
| Companionship need | 4/ 5 |
| Trainability | 4/ 5 |
| Barking | 1/ 5 |
| Good with children | 3/ 5 |
| Good with other dogs | 3/ 5 |
| Heat tolerance | 1/ 5 |
| Cold tolerance | 2/ 5 |
Health
This page is general information compiled from published sources. It is not veterinary, legal or purchase advice. Dogs vary within a breed — talk to a vet or a reputable breeder about the dog in front of you.
Health notes are not veterinary advice. Conditions listed are those reported for the breed, not a diagnosis of any dog. Always consult a veterinarian.
Hip dysplasia
Commonly reported in the breed; breeders screen hips by X-ray. Ask your vet about hip screening and about keeping your dog lean and fit.
Elbow dysplasia
Commonly reported in the breed; breeders screen elbows by X-ray. Ask your vet if you notice front-leg lameness, especially in a growing dog.
Inherited eye conditions
Various inherited eye conditions are reported in the breed; annual eye examinations by a veterinary ophthalmologist are recommended for breeding stock. Ask your vet about eye screening.
Heart conditions
Certain heart conditions are reported in the breed; breeders may have breeding stock examined by a veterinary cardiologist. Ask your vet about heart checks at routine visits.
Bloat (gastric dilatation-volvulus)
Deep-chested dogs of this breed are at risk of bloat, a life-threatening emergency. Ask your vet about the warning signs and prevention options.
Hypothyroidism
Hypothyroidism is reported in the breed. Ask your vet about thyroid testing if you notice weight gain, lethargy or coat changes.
Brachycephalic airway syndrome
As a flat-faced breed, breathing difficulties and heat intolerance are commonly reported. Ask your vet to assess breathing, keep exercise gentle in hot, humid weather and use a harness rather than a collar.
Cancer
Certain cancers are reported at higher rates in the breed. Ask your vet about regular check-ups and about any new lumps.
Behaviour
Bold guardian, docile with family
The CKC says the Bullmastiff is bold, fearless and courageous, a very dependable guard dog, yet docile and easygoing with those it knows and an excellent family companion; the AKC calls it biddable and reliable but says, as with any large guarding dog, training and socialisation must begin early, while the puppy is still manageable.
Walker, not runner
The AKC says Bullmastiffs enjoy daily brisk walks and outdoor play but are not the breed for people who want a running partner, that puppies should not be over-exercised during periods of rapid growth, and that secure fencing is a must; the CKC says it is not a high-energy dog, though capable of turning on the speed or being playful when the occasion demands.
Energy and exercise
Energy level is rated 4/5 (high) on the AKC breed-trait chart. The Royal Kennel Club puts its exercise need at "more than 2 hours per day".
Training and barking
AKC trait chart: trainability 4/5, barking level 1/5. Individual dogs vary; early socialisation and reward-based training are recommended for every breed.
Official guidance
Summaries of official documents are ours; the source is linked. Breed standards, laws and licensing rules change — check the issuing body for the current version.
American Kennel Club — Bullmastiff
Breed overview, breed-trait chart, history, official standard summary and health notes from the AKC and the national parent club.
Read the sourceAccessed 2026-09-09
Canadian Kennel Club — Bullmastiff (Working Dogs)
Origin, temperament, activity level, height/weight, coat and grooming as described by the Canadian Kennel Club.
Read the sourceAccessed 2026-09-09
The Royal Kennel Club — Bullmastiff
Breed characteristics (size large, exercise more than 2 hours per day, lifespan under 10 years), plus the recommended pre-breeding health schemes and DNA tests.
Read the sourceAccessed 2026-09-09
FCI nomenclature — Bullmastiff (standard no. 157, group 2)
FCI breed nomenclature entry with the official breed standard PDF in English, French, German and Spanish.
Read the sourceAccessed 2026-09-09
What owners say
Owner advice is quoted from public community posts and reflects those owners' opinions, not PocketPaw's position. It is unverified and not a substitute for professional advice. Each item links to where it was said.
“The parent club's 'Getting to know the Bullmastiff' page states in capitals that the Bullmastiff is not the breed for everyone: it is fearless and confident yet docile, territorial and possessive, and needs an owner who can set household rules rather than a permissive one; obedience class is treated as mandatory for socialisation and control, puppies should have slow, short walks that build gradually with no high-impact activity until well over 18 months, and owners should expect more drool than most breeds.”
— American Bullmastiff Association — About the Breed via breed clubWorldwide2026-09-09
Sources
- [1]Bullmastiff — Dog Breed Information — American Kennel Club (Accessed 2026-09-09)
- [2]Bullmastiff — Choosing a Breed — Canadian Kennel Club (Accessed 2026-09-09)
- [3]Bullmastiff — Breeds A to Z — The Royal Kennel Club (Accessed 2026-09-09)
- [4]Bullmastiff — FCI standard no. 157 — Fédération Cynologique Internationale (Accessed 2026-09-09)
- [5]How do I help my dog adjust to spending time alone? — The Royal Kennel Club (Accessed 2026-09-09)
- [6]Incidence and risk factors for heat-related illness (heatstroke) in UK dogs under primary veterinary care in 2016 (Hall, Carter & O'Neill, Scientific Reports 10:9128) — Nature / Scientific Reports (Accessed 2026-09-09)
- [7]About the Breed — American Bullmastiff Association — American Bullmastiff Association (public breed information) (Accessed 2026-09-09)
Still have questions?
Ask owners on the PawMunity forum — every breed has its own board.
Breed data compiled by PocketPaw from the sources credited on each entry. Text and layout © 2026 NextPath Solutions Limited. Please link to a page rather than copying it.