The Bullmastiff is a 100-to-130-pound guarding dog bred to silently pin and hold a poacher without mauling him — and the two facts that should drive any adoption decision are its short lifespan and its physical power. This breed typically lives only 7-9 years and is strong enough that an untrained adult can pull a person off their feet without trying. If you are not prepared to start serious training while the dog is a manageable puppy, and not prepared for a relatively brief life with a real cancer burden, the Bullmastiff is the wrong breed — however much you love the calm, devoted temperament, which is genuinely excellent. Physically the Bullmastiff is a broad, muscular, deep-chested dog with a large square head and a short coat in fawn, red, or brindle, always with a dark mask. It drools, snores, and is sensitive to heat — the brachycephalic-leaning head means it overheats fast and tolerates exertion in warm weather poorly. Temperament is the breed's best feature: calm, confident, deeply devoted to family, naturally protective without training to be, and typically gentle and patient with children it is raised with. It is not hyperactive — adults are couch-companions with moderate exercise needs. The flip side is independence and a strong guarding instinct: Bullmastiffs can be dog-aggressive (especially same-sex), wary of strangers, and stubborn, and their size makes any of these traits a serious problem if not shaped early. Who the Bullmastiff is right for: an owner who wants a calm, devoted, lower-energy guardian, will commit to early training and socialization while the dog is small, and accepts a short life with significant veterinary costs. Who it is wrong for: first-time owners, anyone unable to physically manage a powerful dog, hot climates without climate control, or those not ready for the breed's brief lifespan.
Life Span
7–9 years
Weight
45.4–59 kg
Height
61–68.6 cm
moderate
Exercise
moderate
Grooming
moderate
Shedding
Yes
Good with Kids
Yes
Good with Pets
Friendly
Apartment
The Bullmastiff was developed in 19th-century England by gamekeepers who needed a dog to protect estates from poachers. Crossing roughly 60% Mastiff for size and steadiness with about 40% Old English Bulldog for tenacity and courage, they produced the 'Gamekeeper's Night Dog': fast and quiet enough to track a poacher in the dark, powerful enough to knock him down and hold him, and biddable enough not to maul. The breed was bred for a dark coat to…
Bullmastiff dog breed portrait
The Bullmastiff belongs to the Working Group.
The average lifespan of a Bullmastiff is 7 to 9 years.
Bullmastiff dogs are valued for their affectionate, loyal, brave nature.
As an Amazon Associate, we earn from qualifying purchases made through these links, at no extra cost to you.
Detailed cost data for Bullmastiff is not yet available. Check back soon!
Bullmastiff care centers on early control, heat and weight management, and cancer/bloat vigilance — the coat is trivial. Training: this is the urgent one. Start socialization and reward-based obedience in the first 8-16 weeks, while the dog still weighs less than you can control. A trained, socialized Bullmastiff is a model citizen; an untrained 120-pound one with a guarding instinct is dangerous and unmanageable. Socialize broadly to people and other dogs early to temper the natural wariness and same-sex dog aggression. Exercise: moderate, not heavy — two 20-30 minute walks plus light play daily for an adult. Critically, protect growing joints: keep puppies off stairs, slick floors, and forced exercise until growth plates close (about 18 months), and never let a Bullmastiff exercise hard in heat. The flat-ish face means rapid overheating; exercise in the cool of the day and provide shade, water, and air conditioning in summer. Weight: lean is non-negotiable. Excess weight on this frame accelerates hip and elbow arthritis and worsens every other risk. Feed two measured meals, keep ribs easily felt, weigh monthly. Feeding: deep-chested and high bloat-risk — two smaller measured meals from a slow feeder, no gulping, and an hour of rest after eating. Grooming: weekly brush; clean facial folds and dry them to prevent fold infection; expect drool — keep towels handy. Decision rule: a Bullmastiff with a swollen hard belly, unproductive retching, and restlessness is bloating — go to the emergency vet immediately; and any new limb lameness or firm swelling in a middle-aged or older Bullmastiff is a same-week vet visit, because osteosarcoma is common in the breed and early imaging changes outcomes.
Dive deeper into everything Bullmastiff — costs, care, and expert insights.
How Much Does a Bullmastiff Cost?
Purchase price, monthly costs, and lifetime expenses
Bullmastiff Care Guide
## Bullmastiff Care Overview This Bullmastiff care guide gives owners a practical plan for daily...
Considering a cat instead?
Browse Cats Breeds
