Giant dog breeds under primary veterinary care in the UK: demography, common disorders and mortality

BACKGROUND: The domestic dog is the most phenotypically variable mammalian species on earth but there is limited evidence on the overall health patterns within the subset of giant dog breeds. A VetCompass cohort study design was used to report the demography, one-year prevalence of common disorders and mortality of giant breed dogs under UK primary veterinary care during 2019. RESULTS: Giant breed dogs from 29 breeds combined to comprise 28,345 (1.26%) from 2,250,417 study dogs. The most common giant breeds were Dogue de Bordeaux, Alaskan Malamute and Akita. Median adult bodyweight overall of giant breed dogs overall was 48.8 kg (IQR 40.4-58.0, range 25.0-100.0). Overall, 73.8% of giant breed dogs had at least one disorder recorded during 2019. The most common precise-level disorders were otitis externa (8.16%, 95% CI: 7.34-8.97), overweight/obesity (8.02%, 95% CI: 7.21-8.83) and aggression (5.56%, 95% CI: 4.88-6.24). The most common grouped-level disorders were dermatological (15.9%, 95% CI: 14.8-17.0), musculoskeletal (13.5%, 95% CI: 12.5-14.5) and aural disorders (12.0%, 95% CI: 11.0-12.9). Among 1,068 giant breed dogs recorded as having died, the median age at death was 8.94 years (IQR 6.96-10.9, range 0.00-16.1). The most common grouped-level precision causes of death were neoplasia (12.4%, 95% CI: 10.4-14.3), collapse (9.46%, 95% CI: 7.70-11.2) and heart disorder (4.12%, 95% CI: 2.93-5.31). CONCLUSIONS: The current results provide some evidence of higher disorder burden and shorter lifespans in giant breed dogs overall compared to the wider population of dogs that raises concerns about negative impacts on both the quality and quantity of life resulting from our human selection for giantism in dogs. These findings suggest value from considering setting international welfare-based limits for height and bodyweight exaggerations selected in giant dogs.