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Animal register · DogIn the app

Mastiff

English Mastiff, Old English Mastiff

The Mastiff is a very large guarding breed from Great Britain. The FCI standard describes a combination of grandeur and courage — calm, affectionate to its owners but capable of guarding — with a square-looking head, a broad, deep and powerful body and a short, close-lying coat in apricot, fawn or brindle. PDSA gives an average height of 71–78 cm and an average weight of 80–85 kg and notes that The Kennel Club classes the Mastiff in Category Three: breeds with visible conformational issues that can cause pain, discomfort or health problems.

PDSA recommends around an hour of exercise a day for adult dogs — but no over-exercising while a puppy's bones and joints are still developing — grooming once a week with daily cleaning of the facial wrinkles, and gives an average lifespan of under 10 years. PetMD calls Mastiffs great family dogs for homes with children who understand how to interact with pets, though perhaps not with toddlers or babies because of their size; they tend to do well with other pets introduced during puppyhood, drool a lot, and should not exercise for an hour before and after meals because of the risk of bloat.

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

Updated:

Mastiff — photo (AI)
AI-generated photo

At a glance

Size
large — PDSA S370
Adult weight
males 80–85 kg, females 80–85 kg — PDSA S370
Daily exercise
at least 1 hour a day — PDSA S370
Lifespan
median 9 years — Scientific Reports S54; less than 10 years — PDSA S370

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

Who it suits

Good for:

  • family lifeS374
  • families with childrenS374
  • homes with other petsS374

Keep in mind:

  • large dog — not for homes with small childrenS374
  • shorter lifespanS370
  • eyelids and eyes — check eye testsS370S375
  • sensitive skin — prone to itching and inflammationS370S375
  • hips and hind legs — check joint healthS370S375
  • shedsS374
  • drools — keep a cloth at handS374

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: at least 1 hour a day — PDSA S370

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 9 years — Scientific Reports S54
  • Lifespan: less than 10 years — PDSA S370

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 — PDSA S370
  • Height at the withers: males 71–78 cm, females 71–78 cm — PDSA S370
  • Adult weight: males 80–85 kg, females 80–85 kg — PDSA S370

Training

  • No. 72 in Stanley Coren's ranking of working and obedience intelligence. — Wikipedia S35
  • FCI standard no. 264, group 2 (pinscher and schnauzer types, molossoid breeds and Swiss mountain and cattle dogs); origin: Great Britain. — FCI S371

Questions and answers

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

How much exercise does a Mastiff need?

According to our sources, the Mastiff needs this much exercise: at least 1 hour a day — PDSA S370.

How long does a Mastiff live?

According to our sources, the lifespan of the Mastiff is: median 9 years — Scientific Reports S54; less than 10 years — PDSA S370. The sources give different values, so each one is listed.

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

Size and adult weight of the Mastiff, according to our sources: Size: large — PDSA S370; Adult weight: males 80–85 kg, females 80–85 kg — PDSA S370.

Who is the Mastiff a good fit for?

Our sources describe the Mastiff as a good fit for: family life — PetMD S374; families with children — PetMD S374; homes with other pets — PetMD S374. Keep in mind: large dog — not for homes with small children — PetMD S374; shorter lifespan — PDSA S370; eyelids and eyes — check eye tests — PDSA, The Mastiff Association S370S375; sensitive skin — prone to itching and inflammation — PDSA, The Mastiff Association S370S375; hips and hind legs — check joint health — PDSA, The Mastiff Association S370S375; sheds — PetMD S374; drools — keep a cloth at hand — PetMD S374.

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 6,000 from month 6
Young dogmonth 926,000 steps
Adultmonth 36 (3 years)26,000 steps
Seniormonth 81 (6.8 years)24,500 steps
  • Step goal = minutes of daily exercise × 100 steps: an adult gets 1 hour, so 6,000 steps a day.
  • Learns commands more slowly than the mixed breed of the free plan (0.5× its speed).
  • Becomes a senior in month 81 (6.8 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, Scientific Reports, PDSA S10S11S14S18S19S21S24S35S45S54S370

Health

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

  • Bloat (gastric dilatation-volvulus), where the stomach twists, can occur in the breed — it is an emergency that needs a vet straight away. — PDSA S370
  • Eyelid problems can occur in the breed: eyelids that turn inwards (entropion) or outwards (ectropion), and cherry eye, where the third eyelid pops out. — PDSA S370
  • Skin allergies (atopy) that cause itching can occur in the breed, and the folds of skin on the face need cleaning every day. — PDSA S370
  • Can be prone to hip and elbow dysplasia; breeders are advised to have the parents' hips and elbows tested before breeding. — PDSA S370
  • Cardiomyopathy, an enlarged heart caused by a weakening of the heart muscle, can occur in the breed. — PDSA S370
  • Wobbler syndrome, where unstable bones in the neck press on the spinal cord and weaken the back legs, can occur in the breed. — PDSA S370

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

We have not yet found a reliable source that lists health tests for the parents of this breed. 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. S54Scientific Reports (LJMU repository copy) — Author Correction: Longevity of companion dog breeds: those at risk from early death (McMillan et al. 2024, doi:10.1038/s41598-023-50458-w) (PDF)https://researchonline.ljmu.ac.uk/id/eprint/22506/8/Author%20Correction%20Longevity.pdf
  11. S370PDSA — Mastiff — breed guidehttps://www.pdsa.org.uk/pet-help-and-advice/looking-after-your-pet/puppies-dogs/large-dogs/mastiff
  12. S371FCI — FCI-Standard N° 264 — Mastiff (EN PDF; date of publication of the official valid standard 13.10.2010)https://dev.fci.be/Nomenclature/Standards/264g02-en.pdf
  13. S374PetMD — T. Kho-Pelfrey, DVM, reviewed by T. Manucy, DVM (updated Jul. 1, 2025) — Mastiff (English Mastiff) Dog Breed Health and Carehttps://www.petmd.com/dog/breeds/mastiff
  14. S375The Mastiff Association (UK breed club) — Breed Watch (reproduces the Kennel Club Breed Watch entry 'Mastiff - Category 3')https://www.mastiffassociation.uk/breed-watch
  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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