The Canine Ledger

Breed and Lifespan: What the UK Primary-Care Data Shows

One UK study gave French Bulldogs a life expectancy of 4.5 years. Another found a median of 9.8. Why breed lifespan figures differ, and how to read them.

Written by thecanineledger

In 2022, a study of 30,563 UK dogs that had died under primary veterinary care put the French Bulldog’s life expectancy at birth at 4.53 years, the shortest of the 18 breeds it examined (Teng et al., Scientific Reports 2022). Two years later, a study of 584,734 UK dogs gave the breed a median survival of 9.8 years (McMillan et al., Scientific Reports 2024).

While both studies are large and careful, they measured different things in different populations. This page explains what the figures mean, why they differ, and what they can and can’t tell you about your own dog.

1. Two big UK studies

Teng 2022. This study used VetCompass records from UK veterinary practices. It built life tables for dogs that died between January 2016 and July 2020. The headline: “life expectancy at age 0 was 11.23” years for all dogs.

McMillan 2024. This study merged records from 18 sources, “including rehoming and welfare organisations, breed registries, pet insurance companies, veterinary corporations, and university based veterinary archives.” It covered 584,734 dogs, of which 284,734 had died.

Different measures. Teng’s figure is life expectancy at birth. The authors say this “equates to the mean age at death of dogs across all ages.” McMillan reports median survival, the age by which half the dogs had died. A mean is pulled down by deaths at a young age; a median is not.

Our note: The mean-versus-median explanation is ours and simplifies the method.

2. Why the French Bulldog figures differ so much

The Teng authors explain the 4.53 themselves. French Bulldog registrations with the UK Kennel Club “rose steeply from 2771 in 2011 to 39,266 in 2020”. That suggests the French Bulldogs in their data “are biased towards younger dogs that contribute proportionately more deaths in younger ages in the life table.”

They also mention “high health risks in early life” and “a relatively small sample size (n = 232)”.

The lesson. A breed that has recently become popular has few old dogs yet. Early deaths dominate its figures until the population ages. The 4.53-year figure is real for that dataset, but it isn’t a prediction for a French Bulldog puppy bought today.

McMillan’s own caution. That study notes that insurance data may under-represent some breeds, “especially those of high disease risk, such as brachycephalic breeds, due to the elevated cost of insurance”.

3. What both studies agree on

Flat-faced breeds live shorter lives. Teng found that “many brachycephalic breeds (i.e., breeds of dogs with a short, flat face) had a relatively short life expectancy”, with English Bulldogs at 7.39 years and Pugs at 7.65. McMillan found a median of 11.2 years for flat-faced purebreds, against 12.8 for those with medium-length faces.

Females live slightly longer. Teng: females 11.41 years, males 11.07. McMillan: females 12.7, males 12.4.

Bigger dogs die younger. McMillan found medians of 12.7 years for small purebreds and 11.9 for large ones.

The longest-lived. In Teng’s 18 breeds, the Jack Russell Terrier had the longest life expectancy, at 12.72 years.

→ Brachycephalic Airway Disease: Grading, Surgery, and What “Normal Snoring” Hides

4. Where they disagree: purebred or crossbred

Teng gave crossbred dogs a life expectancy of 11.82 years, close to the overall 11.23 and to Labradors at 11.77.

McMillan found that purebreds as a group lived longer, with a median of 12.7 years against 12.0 for crossbreds. It found that “47.1% of purebreds present a greater median survival estimate than crossbreds, only 25.8% present a shorter life expectancy than crossbreds, and 27.1% did not vary significantly.”

Why that might be. The studies used different sources, and McMillan’s crossbred group includes rescue and rehoming records. The authors note that specific sources “may introduce representation bias”.

Our note: McMillan’s authors say they “incorporated rehoming and welfare charity datasets, where crossbred dogs have been reported to represent 44–87.8% of the UK rehoming population”. They couldn’t compare sources, because of “restrictions stipulated within data sharing agreements with project participants”. So no one outside the project can say how many crossbreds came from each source.

The lesson. “Mixed breeds live longer” is not a safe general rule. It depends on which mix, and which data.

→ Choosing a Breed or a Mix: The Health Data Breeders Don’t Lead With

5. What this means for your dog

  • A breed figure is an average for a population, not a forecast for one dog.
  • Both studies are UK only. Breeding lines, healthcare and causes of death differ between countries.
  • A breed’s figures can shift as its popularity changes.
  • What you can control, such as weight and preventive care, isn’t captured in a breed average.

Our note: The last bullet is our framing. Neither study measures the effect of owner care on lifespan.

→ Preventive Care Without the Upsell: What Your Dog Actually Needs · → Is It Old Age, or Something Treatable? A Guide to Your Senior Dog

6. What we could not verify

Commonly saidWhat we found
“French Bulldogs live about four and a half years”That figure is skewed. The authors say young dogs were over-represented. Another study found a median of 9.8.
“Mixed breeds always live longer”Not in the largest UK study. It found purebreds lived slightly longer as a group.
“Small dogs live longest”Broadly, yes. Small purebreds had a longer median than large ones in the 2024 study.
“These figures apply everywhere”No. Both studies are UK only.
“Breed decides how long my dog will live”No. These are population averages, not predictions for one dog.

Sources

Always confirm with your vet before acting on anything on this page.