Conclusion: regular-headed, female, small dog breeds live the longest! 🐶🐕🦺. The study cited below tells us that for purebred dogs the average lifespan depends on the shape of the head and its size. Gender also has an impact. Head shaped is defined below:
- mesocephalic – means regular head.
- dolichocephalic means a head that is longer than average relative to its width.
- brachycephalic means shortened head.
- Average ‘survival’ (lifespan or life expectancy) for mesocephalic purebred dogs was 12.8 years.
- For brachycephalic dogs the lifespan was 11.2 years (average).
- For dolichocephalic dogs the lifespan was 12.1 years (average).
- For small, female dolichocephalic dogs the lifespan was 13.3 years (longest lifespan on average).
Comment: regular-headed dogs live the longest. Long-faced dogs live longer than smushed faced dogs but they live shorter lives than regular-faced dogs.
- Medium-sized brachycephalic dog breeds (compared to small dogs) ‘presented a 2.69 fold faster time to death’.
- Large-sized brachycephalic dog breeds (compared to small dogs) ‘presented a 1.92 fold faster time to death’.
- The worst impact in terms of life expectancy compared to female, regular-headed dogs is experienced by the medium-sized male brachycephalic dog breeds. This would appear to be the shortest-lived dog breed.
Comment: this can only mean that smushed-faced (flat-faced) large and medium-sized dog breeds have around half the live expectancy of small dog breeds with the same flat-faced (shortened muzzle). This would give them relatively very short lives.
That said the French bulldog is a small, flat-faced dog breed with the shortest lifespan and the most unhealthy physiology of all the breeds. There appears to be exceptions to the above formula.
Techical quote from the study
Median survival for mesocephalic purebreds was 12.8 years (12.7–12.8, 𝑛 = 267,753, events = 138,357), with an accelerated time to death for brachycephalic and dolichocephalic purebreds at 11.2 years (11.2–11.3, 𝑛 = 88,103, events = 40,644, HR 1.4, 1.4–1.4, p < 0.001) and 12.1 years (12.0–12.1, 𝑛 = 66,369, events = 33,224, HR 1.1, 1.1–1.1, p < 0.001), respectively. An interaction was evident between cephalic index and size. In comparison with longest living small-dolichocephalic breeds (x̃ = 13.3, 13.2–13.4), brachycephalic-medium and brachycephalic-large sized breeds presented a 2.69 (2.59–2.79, x̃ = 9.4, 9.3–9.5, p < 0.001) and 1.92 (1.87–1.98, x̃ = 10.7, 10.6–10.8, p < 0.001) fold faster time to death, respectively (Fig. S3). However, a further interaction was noted, between cephalic index, size, and sex (Fig. 4). Similar to previous findings, in comparison with longest living small-dolichocephalic-female breeds (x̃ = 13.3, 13.2–13.4), medium-brachycephalic male and female breeds presented a 2.85 (2.71–2.3, x̃ = 9.1, 9.0–9.3, p < 0.001) and 2.69 (2.54–2.83, x̃ = 9.6, 9.4–9.8, p < 0.001) fold faster time to death, respectively. Furthermore, variation in longevity between the three cephalic indices were most apparent within medium sized dogs.
AI’s interpretation of this study as a whole. I have focused on size, head shape and lifespan linkage
The study titled “Longevity of companion dog breeds: those at risk from early death” investigates the variation in life expectancy among different dog breeds. Here are the key findings:
- Dataset: The study analyzed a dataset of 584,734 unique dogs in the UK, including 284,734 deceased dogs.
- Factors: They examined longevity estimates based on parental lineage (purebred vs. crossbred), breed (155 breeds), body size (large, medium, small), sex (male, female), and cephalic index (brachycephalic, mesocephalic, dolichocephalic).
- Phylogenetic Clades: The research found evidence that breed lifespan is associated with canine evolutionary history, including domestication and artificial selection.
- Implications: This information can inform discussions on pedigree health and help owners, breeders, and policymakers make better decisions regarding canine welfare.
Additionally, other studies have identified specific long-lived breeds, such as Shiba Inus and miniature dachshunds, while flat-faced dogs tend to have shorter lifespans.
Lifespan affected by head shape – AI’s interpretation
The study found that head shape (cephalic index) was associated with lifespan in dogs. Specifically, brachycephalic (short-faced) breeds tend to have shorter lifespans compared to mesocephalic (medium-faced) and dolichocephalic (long-faced) breeds. This relationship likely results from health issues related to brachycephalic features, such as respiratory problems and dental issues. However, it’s essential to note that individual variation exists within each breed, and other factors also contribute to overall longevity. 🐶📊
What are the short-faced dog breeds?
Brachycephalic dog breeds, also known as short-muzzled or short-nosed dogs, are prone to long-term health problems due to their unique skull shape. Here are some common examples of brachycephalic breeds:
- Pug
- Boston Terrier
- Pekingese
- Boxer
- Bulldog
- Shih Tzu
- Bull Mastiff
These breeds often face issues related to breathing difficulties, eye problems, bones, and gait. Their compressed skulls result in undersized facial bones and soft tissues, making them especially susceptible to conditions like brachycephalic obstructive airway syndrome (BOAS).
How can owners improve the quality of life for these breeds?
Certainly! Improving the quality of life for brachycephalic breeds involves several considerations:
- Health Monitoring: Regular veterinary check-ups are crucial. Monitor their breathing, weight, and overall health.
- Weight Management: Maintain a healthy weight to reduce strain on their respiratory system and joints.
- Exercise: Engage in low-impact exercises to avoid overexertion. Short walks and playtime are ideal.
- Cool Environment: Brachycephalic dogs are prone to overheating. Keep them in a cool environment, especially during hot weather.
- Diet: Choose high-quality, easily digestible food. Avoid foods that can cause gas or bloating.
- Breathing Aids: Some brachycephalic dogs benefit from nasal dilators or surgery to improve airflow.
- Dental Care: Regular dental hygiene prevents dental issues common in these breeds.
The study
Citation: “Longevity of companion dog breeds: those at risk from early death” by Kirsten M. McMillan, Jon Bielby, Carys L. Williams, Melissa M. Upjohn, Rachel A. Casey and Robert M. Christley, 1 February 2024, Scientific Reports.
DOI: 10.1038/s41598-023-50458-w
