How Long Do Dogs Live? Life Expectancy by Breed and Size

How long do dogs live?

Dogs in the UK live a median of 12.5 years, and 95% of them had died by about 18 years. That comes from McMillan and colleagues (Scientific Reports, 2024), who analyzed 584,734 dogs, of which 284,734 had died.

The PetMD page, updated January 9, 2026, and the American Kennel Club page, last updated May 27, 2021, give size-based ranges without naming studies for those ranges. This page uses the published numbers instead.

A median is the age at which half the dogs have died. Half of all dogs live longer than 12.5 years, and half live shorter. Use the tables below to place your dog’s breed and size in the range.

What is the average lifespan of a dog?

The average lifespan of a dog is about 12 to 13 years in the best large datasets. UK and US studies give slightly different figures because they measure different things.

Study	Dogs	What it measures	Result
McMillan et al., 2024 (UK)	584,734 (284,734 deceased)	Median age at death, including dogs still alive	12.5 years (purebred 12.7, crossbred 12.0)
Teng et al., 2022 (UK, VetCompass)	30,563 deaths, 2016 to 2020	Life expectancy at birth	11.23 years (female 11.41, male 11.07)
Montoya et al., 2023 (US, Banfield clinics)	13,292,929	Life expectancy at birth, 2013 to 2019	12.69 years (female 12.76, male 12.63)

Teng estimated life expectancy at birth from recorded deaths, but puppy deaths before veterinary registration could be missing. McMillan’s figure is a median from a survival curve. The US study used different sampling and methods again, so the three numbers sit close together without matching.

For an adult dog, remaining life expectancy at its current age is the number that fits. Teng’s life tables give it year by year, and neither a birth figure nor an unconditional median accounts for the years your dog has already lived.

Body weight shows up in the US data too: dogs with an ideal body condition score (3 out of 5) had a life expectancy at birth of 13.18 years, and obese dogs (5 out of 5) had 11.71.

Do small dogs live longer than big dogs?

Small dogs live slightly longer than large dogs on average, by about 10 months in the 2024 UK study.

McMillan and colleagues sorted 155 purebred breeds into small, medium and large. Their medians:

Group (purebred)	Dogs	Median lifespan	Gap to small
Small	223,222	12.7 years	none
Medium	73,532	12.5 years	2 months shorter
Large	123,072	11.9 years	10 months shorter

The arithmetic: 12.7 minus 11.9 is 0.8 years, or about 10 months. The study did not include a separate giant class.

Sex adds to the gap. Small females had a median of 12.8 years and large males 11.8, a full year apart. Large males also faced a 1.28 times faster time to death than the longest-lived group, small females, which the authors report with a 95% interval of 1.26 to 1.29.

Within the same size group, breeds differ by many years.

Dog life expectancy by breed

Dog life expectancy by breed ranges from 5.4 years for the Caucasian Shepherd Dog to 15.4 years for the Lancashire Heeler in the 2024 UK study.

The table lists medians from McMillan et al. (2024) for breeds the authors flagged as least or most at risk of early death, plus the Border Collie, Labrador Retriever and Pug from their survival-curve figure. Breeds with few dogs in the data have wider uncertainty at the extremes.

Breed	Median lifespan (years)
Lancashire Heeler	15.4
Tibetan Spaniel	15.2
Shiba Inu	14.6
Papillon	14.5
Lakeland Terrier, Schipperke, Border Terrier	14.2
Italian Greyhound, Miniature Dachshund	14.0
Border Collie, Labrador Retriever	13.1
Pug	11.6
Bulldog, French Bulldog	9.8
St Bernard, Bloodhound, Affenpinscher, Neapolitan Mastiff	9.3
Mastiff	9.0
Cane Corso	8.1
Presa Canario	7.7
Caucasian Shepherd Dog	5.4

The 2022 Teng study reached the same pattern with a different method. Jack Russell Terriers had the longest life expectancy at birth (12.72 years) and French Bulldogs the shortest (4.53 years). The French Bulldog gap, 9.8 against 4.53, shows how much method and dataset move a single breed’s number.

French Bulldogs also point to head shape, which the next section covers. To turn these numbers into a start age for your own breed, see when a dog is considered a senior.

Do flat-faced dogs live shorter lives?

Flat-faced (brachycephalic) dogs live shorter lives than other head shapes, with a median of 11.2 years against 12.8 for mesocephalic breeds in the 2024 UK study.

McMillan and colleagues compared three head shapes among purebreds:

• Mesocephalic (average-length muzzle): 12.8 years
• Dolichocephalic (long muzzle): 12.1 years
• Brachycephalic (short muzzle): 11.2 years

That is a gap of 1.6 years, or about 19 months, between mesocephalic and brachycephalic dogs. Head shape and size interact. Medium brachycephalic breeds had a median of 9.4 years, while small long-muzzled breeds had 13.3. The authors report that medium brachycephalic dogs had a 2.69 times faster time to death than the longest-lived group.

The study measured how long dogs lived, not why. PetMD points to heatstroke and breathing-related deaths in flat-faced breeds such as Bulldogs as a likely driver.

Why do big dogs age faster?

Big dogs age faster at the molecular level, according to a 2026 Science paper that found accelerated epigenetic aging in larger dogs.

The study, led by Mariner and the Dog Aging Project Consortium and published October 8, 2026, used 1,640 methylomes from 894 dogs. A methylome is a map of chemical tags on DNA. The team built an epigenetic clock that predicted mortality. They found that larger and male dogs, who are shorter lived, showed accelerated molecular aging. Size-linked changes were strongest at transposable elements, stretches of DNA that can move within the genome.

The abstract reports no tested diet, supplement or exercise plan that slows this process. It explains the pattern behind the size gap in the tables above.

What can owners change?

Body condition is the best-supported lever. Breed, size and head shape are fixed, but weight is yours.

• Kealy and colleagues (2002) fed 48 Labrador Retrievers in pairs, one dog 25% less than its pair-mate from 8 weeks of age. The restricted dogs had a significantly longer median life span and later onset of chronic disease.
• Adams and colleagues (2016) followed 39 neutered Labradors with body condition kept between 2 and 4 on a 5-point scale. Keeping lean body mass and gaining fat more slowly were key factors in reaching a longer lifespan.
• The US data above point the same way: ideal-weight dogs had a life expectancy at birth of 13.18 years, and obese dogs 11.71.

Both Labrador studies used one breed in controlled housing. Keep your dog lean and let your vet set the target, because a senior dog that loses weight without trying can be ill: see senior dog losing weight but still eating.

What stays fixed:

• Breed and size. The Mastiff median was 9.0 years; that population figure cannot predict an individual dog’s lifespan.
• Sex. Females had a median about 0.3 years longer than males (12.7 against 12.4).
• Head shape.

One step you can take tonight: write down your dog’s breed, age and current weight, and ask your vet at the next visit what to watch for at this age. If your dog’s back legs are failing or it collapses, call a vet now; our guide on an old dog’s back legs giving out explains what that looks like. For the end of life, see signs an elderly dog is dying.

How to read these numbers

These numbers describe populations, and your dog sits somewhere inside them.

• A median is a middle point. About 1 in 20 dogs lived past 18 years, and many died well before 12.
• Both UK datasets describe UK dogs. Teng used veterinary records; McMillan combined veterinary records with registry, insurance, welfare and academic data. The US figure comes from one clinic network.
• PetMD suggests large dogs may die earlier partly because incontinence, cancer and mobility problems are harder to manage in them, which may lead to earlier euthanasia. The studies above do not test that.
• A breed median based on a few hundred dogs is less certain than one based on tens of thousands. The paper’s supplementary table lists the count for each breed.

For a broader view of the later years, see all of our senior dog guides.