A Mastiff's life is short even by giant-breed standards, commonly well under a decade, and that same huge frame carries a serious lifetime risk of sudden, fatal stomach bloat, so you are taking on a very short and potentially very expensive lifespan.
9years, median
3.5 years below the all-dog median of 12.5.
Measured, not estimated: the middle age at death across 584,734 UK dogs, 284,734 of them deceased. Based on 3,259 dogs of this breed. 95% confidence interval 8.9 to 9.2 years. Half lived longer than this, half did not. UK dogs, so treat it as the best available figure rather than a promise about yours.
In the same study, large breeds as a group had a median of 11.9 years and flat-faced breeds 11.2. This breed is large and flat-faced.
McMillan et al. 2024, Scientific Reports 14:531 — open access · CC BY 4.0Health tests to ask the breeder for
Mastiff Club of America sets the tests a Mastiff needs for a CHIC number in the OFA's open database. A CHIC number means the tests were done and the results are public. It does not mean the dog passed them: ask for the results for both parents, or look them up yourself on ofa.org.
- Hip Dysplasia (OFA Evaluation, 24 months or older)
- Elbow Dysplasia (OFA Evaluation, 24 months or older)
- Eye Examination by a boarded ACVO Ophthalmologist (minimum 24 months)
- Cardiac Evaluation (Basic or Advanced Cardiac Exam, 12 months or older)
When to spay or neuter: the guidelines split at 45 pounds grown, five to six months under it and after growth is complete over it, and the UC Davis study gives a guideline by breed for 35 breeds. The spay and neuter page has both, and the two weeks after.
- Autoimmune Thyroiditis (OFA evaluation)
- Canine Multifocal Retinopathy Type 1 (CMR1) DNA test
- Cystinuria Type 3 marker DNA test
- Cystinuria nitroprusside urine test (intact males)
- Degenerative Myelopathy (DM) DNA test
- Patellar Luxation (OFA Evaluation)
- Dominant Progressive Retinal Atrophy (dPRA, Bullmastiff/Mastiff type) DNA test
Test names as the club lists them; checked September 2026. OFA CHIC breed page. How to use this at the breeder: check a breeder.
Adopt a Mastiff near you
Shelters and rescues list Mastiffs and Mastiff mixes on Petfinder. Enter a ZIP code to see who is waiting within 100 miles.
Listings come from Petfinder and open there. Petipedia does not take part in adoptions and earns nothing from them.
Living with a Mastiff
Day to day, a healthy adult Mastiff is genuinely low-key, happy to lie around the house and content with modest exercise, though it still needs some daily activity and space to move. The real cost of the breed is size itself: large food and medication bills, a dog that can accidentally injure a small child or knock over an adult just by leaning or moving, and a working lifespan short enough that many owners face serious mobility or health decline well before the dog turns 8.
Health you should know about
- Short lifespan — commonly cited around 6-10 years, at the shorter end even among giant breeds; giant-breed longevity research consistently finds that size itself shortens lifespan.
- Gastric dilatation-volvulus (bloat) — a sudden, life-threatening twisting of the stomach; deep-chested giant breeds like the Mastiff are among those most at risk, and some owners opt for a preventive gastropexy.
- Hip and elbow dysplasia — very common in a breed this large and heavy, often leading to arthritis.
- Cancer — osteosarcoma (bone cancer), lymphoma, and other cancers are well documented in giant breeds including the Mastiff.
Read the full Dog Care Guide first — costs, daily time, and everything a dog needs before you choose a breed.
Naming a Mastiff? British dog and cat names, 89 of them, with what they mean.
Sources — 2 references
Last reviewed October 2026. 2 sources listed below. Written and maintained by Petdeals.io. General care information, not veterinary advice — for a sick animal, call a vet.