Dog breed · Working / Guardian
Bullmastiff
A massive but generally calm guardian bred by nineteenth-century English gamekeepers to silently pursue and pin poachers without mauling them. At home Bullmastiffs are famously placid and devoted.
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Breed characteristics
- Group
- Working / Guardian
- Origin
- England
- Size
- Giant
- Weight
- 41–59 kg (90–130 lb)
- Height
- 61–69 cm
- Lifespan
- 7–9 years
- Coat
- Short, dense, weather-resistant coat
- Temperament
- CalmProtectiveLoyalDocile at home
History
Developed around 1860 by crossing Mastiffs with Bulldogs to create a fast, powerful but controllable gamekeeper's dog.
Appearance
A broad-headed, heavily built dog with a short muzzle and a dense fawn, red or brindle coat.
Exercise and activity
Moderate — 30–45 minutes of walking daily; too much high-impact exercise as a puppy can stress developing joints in such a large breed.
Care and grooming
Wipe facial wrinkles and manage drool; the size and strength mean early lead training matters even though the breed is not naturally hyperactive.
Health considerations
- Hip and elbow dysplasia
- Gastric dilatation-volvulus (bloat)
- Certain cancers, including lymphoma and mast cell tumours
- Entropion
- Hypothyroidism
Honest challenges
Before choosing a Bullmastiff
- Treat the breed profile as a starting point, not a guarantee of temperament. Meet the individual and discuss its history, needs and behaviour with the rescue or responsible breeder.
- Check your routine can support the activity described here: Moderate — 30–45 minutes of walking daily; too much high-impact exercise as a puppy can stress developing joints in such a large breed. Allow for age, weather, health and recovery rather than imposing a fixed target.
- Ask the breeder or rescue and your vet about problems reported in this breed (such as Hip and elbow dysplasia, Gastric dilatation-volvulus (bloat), Entropion, Hypothyroidism), which of them have recognised screening tests, and the parents' results where relevant. Screening reduces some uncertainty but cannot promise a healthy lifetime. Bloat has no screening test: learn its emergency signs and ask about prevention.
- Plan grooming, veterinary costs and care during holidays. Children and other pets still need careful introductions and supervision whatever a breed's typical rating.
Educational reference, not an individual diagnosis or a verified professional review. Read our editorial policy.
Guidance libraries and further reading
These organisations publish relevant guidance. Their links are further reading, not evidence that they have reviewed this page.
- RSPCA — animal care and welfare advice across species
- PDSA — veterinary charity pet health advice
- Dogs Trust — dog care, behaviour and welfare advice