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Bullmastiff

Bull Mastiff

The Bullmastiff is an old English guard breed of the 19th century, descended from the Bulldog and the Old English Mastiff; the FCI lists it among the molossoid breeds. Its standard describes a powerful, symmetrical dog showing great strength but not cumbersome — enduring, active, reliable, high-spirited, alert and faithful. Males stand 64–69 cm and weigh 50–59 kg, females 61–66 cm and 41–50 kg. The short, hard coat is any shade of fawn, red or brindle, always with a black muzzle.

The Royal Kennel Club recommends more than two hours of exercise a day and grooming once a week, and the breed usually lives under 10 years. PDSA describes very loyal dogs whose size and power make them better suited to adult-only homes or families with older children; they need early socialisation, ideally have someone at home all the time, have a very strong prey drive, drool a lot and need a gap between eating and exercise.

Available in the 12-week PetPrep Challenge (paid breed).

Updated:

Bullmastiff — photo (AI)
AI-generated photo

At a glance

Size
large — The Royal Kennel Club S567
Adult weight
males 50–59 kg, females 41–50 kg — FCI S566
Daily exercise
more than 2 hours a day — The Royal Kennel Club S567
Brushing
once a week — The Royal Kennel Club S567
Lifespan
median 10.2 years — Dogs Trust S123; less than 10 years — The Royal Kennel Club S567

Key facts from the sources at the bottom of the page. Where sources differ, each value is listed.

Who it suits

Good for:

Keep in mind:

  • needs lots of exercise every dayS567S568
  • shorter muzzle — can have breathing problemsS568
  • large dog — not for homes with small childrenS568
  • powerful dog — needs an experienced ownerS568
  • loves company — best with someone home most of the dayS568
  • shorter lifespanS567S568
  • drools — keep a cloth at handS568
  • strong prey drive — may chase small petsS568

The same tags as in the app. Each tag is backed by the sources listed at the bottom of the page.

What it needs

From breed standards, kennel clubs, veterinary charities and studies. Where sources differ, each one is shown.

Exercise

  • Daily exercise: more than 2 hours a day — The Royal Kennel Club S567

Coat and grooming

  • Coat: short — The Royal Kennel Club S567
  • Brushing: once a week — The Royal Kennel Club S567

Meals

General guidance for dogs (not breed-specific):

  • 8–12 weeks: 4 meals a day — ASPCA S18
  • 3–6 months: 3 meals a day — ASPCA S18
  • 6–12 months: 2 meals a day — ASPCA S18
  • Adult: at least 2 meals a day — VCA Animal Hospitals S19
  • Senior: 2–3 meals a day, smaller portions — Dogs Trust S14

Lifespan

  • Lifespan: median 10.2 years — Dogs Trust S123
  • Lifespan: less than 10 years — The Royal Kennel Club S567

Life stages

  • Reaches adult size at: about 18–24 months (guidance for its size class) — PetMD S10

General guidance for dogs (not breed-specific):

  • Puppy: until about 6–9 months — AAHA S11
  • Young adult: until 3–4 years — AAHA S11
  • Senior: the last 25 % of the expected lifespan — AAHA S11

Size and weight

  • Size: large — The Royal Kennel Club S567
  • Height at the withers: males 64–69 cm, females 61–66 cm — FCI S566
  • Adult weight: males 50–59 kg, females 41–50 kg — FCI S566

Training

  • No. 69 in Stanley Coren's ranking of working and obedience intelligence. — Wikipedia S35
  • FCI standard no. 157, group 2 (pinscher and schnauzer types, molossoid breeds and Swiss mountain and cattle dogs); origin: Great Britain. — FCI S565

Questions and answers

Answered only from the sourced facts on this page; every answer names its sources.

How much exercise does a Bullmastiff need?

According to our sources, the Bullmastiff needs this much exercise: more than 2 hours a day — The Royal Kennel Club S567.

How long does a Bullmastiff live?

According to our sources, the lifespan of the Bullmastiff is: median 10.2 years — Dogs Trust S123; less than 10 years — The Royal Kennel Club S567. The sources give different values, so each one is listed.

How big does a Bullmastiff get and how much does it weigh?

Size and adult weight of the Bullmastiff, according to our sources: Size: large — The Royal Kennel Club S567; Adult weight: males 50–59 kg, females 41–50 kg — FCI S566.

How much grooming does a Bullmastiff need?

Coat and grooming of the Bullmastiff, according to our sources: Brushing: once a week — The Royal Kennel Club S567; Coat: short — The Royal Kennel Club S567.

Who is the Bullmastiff a good fit for?

Our sources describe the Bullmastiff as a good fit for: an active family — The Royal Kennel Club, PDSA S567S568; a large house and garden — The Royal Kennel Club S567. Keep in mind: needs lots of exercise every day — The Royal Kennel Club, PDSA S567S568; shorter muzzle — can have breathing problems — PDSA S568; large dog — not for homes with small children — PDSA S568; powerful dog — needs an experienced owner — PDSA S568; loves company — best with someone home most of the day — PDSA S568; shorter lifespan — The Royal Kennel Club, PDSA S567S568; drools — keep a cloth at hand — PDSA S568; strong prey drive — may chase small pets — PDSA S568.

Game rules, not veterinary advice

How PetPrep simulates it

In PetPrep one real week is one month of the pet's life. These are the rules the game uses for this breed. PetPrep chose them from the sources on this page; they are not care instructions for a real animal.

Life stageStartsMeals a dayDaily step goal
Puppyarrives at 2 months4; from month 3: 3; from month 6: 21,000 steps per month of age (2,000 on arrival), up to 12,000 from month 12
Young dogmonth 929,000 → 12,000 steps
Adultmonth 36 (3 years)212,000 steps
Seniormonth 92 (7.7 years)29,000 steps
  • Step goal = minutes of daily exercise × 100 steps: an adult gets 2 hours, so 12,000 steps a day.
  • Learns commands more slowly than the mixed breed of the free plan (0.7× its speed).
  • Becomes a senior in month 92 (7.7 years) — the last quarter of the breed's expected lifespan.
  • Walks count real steps from Apple Health or Health Connect (with permission, read-only) and the phone's motion sensor — no GPS.
  • Combing once a week.
  • Care: cleaning the skin folds every day — a task for the child.

Each game number is a PetPrep decision recorded with its sources. — PetMD, AAHA, Dogs Trust, ASPCA, VCA Animal Hospitals, The Royal Kennel Club, Purdue University Canine Welfare Science, Wikipedia, British Journal of Sports Medicine, PDSA S10S11S14S18S19S21S24S35S45S123S567S568

Health

For information only, not vet-reviewed. Ask your vet about your own animal.

  • A brachycephalic (short-faced) breed: the shorter face can cause serious breathing problems (brachycephalic obstructive airway syndrome, BOAS). — PDSA S568
  • Bloat (gastric dilatation-volvulus), where the stomach twists, can occur in the breed — it is an emergency that needs a vet straight away. — PDSA S568
  • Can be prone to hip and elbow dysplasia; breeders are advised to have the parents' hips and elbows tested before breeding. — PDSA S568
  • Eyelids that turn inwards (entropion) or outwards (ectropion) can occur in the breed; ask for eye-checked parents. — PDSA S568
  • Certain cancers can occur in the breed. — PDSA S568

Before you buy: what to check with the breeder

Questions to settle before you take a puppy home. The points are advice from vets, welfare charities and kennel clubs; each cites its source.

For every breed

  • See the puppy with its mother, where it was born. — PDSA, RSPCA K1K2
  • The puppy should not leave its mother before 8 weeks of age. — PDSA K1
  • Ask for the pedigree. Under FCI rules a pedigree may be issued for correct parentage only. — FCI K7
  • Ask to see the health-test results of both parents. Which tests matter depends on the breed. — PDSA, British Veterinary Association, FOUR PAWS UK K1K9K10
  • National kennel clubs can set breeding rules that go beyond the FCI's — ask the breed club which tests the parents need. — FCI K7
  • Ask for a written sale contract that records the puppy's background and health. — British Veterinary Association, FOUR PAWS UK K9K10

Laws on the minimum age, microchipping and vaccination differ by country — check the rules where you live.

Health tests of the parents for this breed

Tests the Royal Kennel Club recommends as a minimum

  • Elbow X-ray screening for elbow dysplasia (UK: BVA/KC scheme) — The Royal Kennel Club S567
  • Eye examination by a veterinary eye specialist (UK: BVA/KC/ISDS scheme; for some breeds with gonioscopy) — The Royal Kennel Club S567
  • Hip X-ray screening for hip dysplasia (UK: BVA/KC scheme) — The Royal Kennel Club S567

These lists come from the UK's Royal Kennel Club and are an orientation; national kennel clubs can set their own, stricter rules. Ask the breed club and the breeder which tests the parents have done.

Similar breeds

Other dogs in the register with similar needs — each with sourced facts.

Sources

Every fact on this page cites one of these sources.

  1. S10PetMD — S. C. Mitchell, DVM, DABVP, 2025-05-20 — When Do Dogs Stop Growing?https://www.petmd.com/dog/general-health/when-do-dogs-stop-growing
  2. S11AAHA — 2019 AAHA Canine Life Stage Guidelines — Canine life stage definitionshttps://www.aaha.org/resources/life-stage-canine-2019/canine-life-stage-definitions/
  3. S14Dogs Trust (UK) — Caring for an older doghttps://www.dogstrust.org.uk/dog-advice/life-with-your-dog/at-home/looking-after-an-older-dog
  4. S18ASPCA — General Dog Carehttps://www.aspca.org/pet-care/dog-care/general-dog-care
  5. S19VCA Animal Hospitals (2025-02-21) — Feeding Times and Frequency for Your Doghttps://vcahospitals.com/pets-first/know-your-pet/feeding-times-and-frequency-for-your-dog
  6. S21The Royal Kennel Club (UK) — Puppy feeding tipshttps://www.royalkennelclub.com/health-and-dog-care/health-dog-care/health/health-and-care/a-z-of-health-and-care-issues/puppy-feeding-tips
  7. S24Purdue University Canine Welfare Science (content: Pet Leadership Council 2019, bedogsmart.com) — Dog Fitness and Exercise (PDF)https://caninewelfare.centers.purdue.edu/wp-content/uploads/2022/12/Dog-Fitness-and-Exercise.pdf
  8. S35Wikipedia — The Intelligence of Dogshttps://en.wikipedia.org/wiki/The_Intelligence_of_Dogs
  9. S45British Journal of Sports Medicine (2018) — Tudor-Locke C. et al. How fast is fast enough? Walking cadence (steps/min) as a practical estimate of intensity in adults. doi:10.1136/bjsports-2017-097628https://pmc.ncbi.nlm.nih.gov/articles/PMC6029645
  10. S123Dogs Trust (UK) — Life expectancy for 155 breeds and crossbred group (table of McMillan et al. 2024 data) (PDF)https://www.dogstrust.org.uk/downloads/life-expectancy-breeds-table-2024.pdf
  11. S565FCI — FCI breeds nomenclature — BULLMASTIFF (157)https://www.fci.be/en/nomenclature/BULLMASTIFF-157.html
  12. S566FCI — FCI-Standard N° 157 Bullmastiff, English (PDF; date of publication of the official valid standard 13.10.2010)https://dev.fci.be/Nomenclature/Standards/157g02-en.pdf
  13. S567The Royal Kennel Club — Breeds A to Z — Bullmastiffhttps://www.royalkennelclub.com/search/breeds-a-to-z/breeds/working/bullmastiff/
  14. S568PDSA — Bullmastiff — breed guidehttps://www.pdsa.org.uk/pet-help-and-advice/looking-after-your-pet/puppies-dogs/large-dogs/bullmastiff
  15. K1PDSA — Getting a puppyhttps://www.pdsa.org.uk/pet-help-and-advice/looking-after-your-pet/puppies-dogs/getting-a-puppy
  16. K2RSPCA — Buying a puppyhttps://www.rspca.org.uk/adviceandwelfare/pets/dogs/puppy
  17. K7FCI (copy hosted by Norsk Kennel Klub) — International Breeding Rules of the FCIhttps://nkk2023.stage22.coretrek.no/getfile.php/131987377-1520848467/Dokumenter/Registrering/FCIs%20avlsregler%202013.pdf
  18. K9British Veterinary Association — What should you consider when buying a puppy?https://www.bva.co.uk/news-and-blog/blog-article/what-should-you-consider-when-buying-a-puppy/
  19. K10FOUR PAWS UK — Questions to ask when buying a puppyhttps://www.four-paws.org.uk/our-stories/publications-guides/questions-to-ask-when-buying-a-puppy

PetPrep is a simulation for families. This page is not veterinary advice — for a real animal, ask a vet or the breed club.

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