Research Reveals Health and Lifespan Challenges in Giant Breed Dogs

New research from the Royal Veterinary College (RVC) has revealed that giant dog breeds in the UK live substantially shorter lives than the general dog population and experience higher levels of some disorders, raising concerns about the welfare impacts of breeding for extreme size. These findings provide insights to help prospective owners make more informed decisions and help current owners understand what to expect for their dog’s health over time. The study will also help veterinarians support the welfare of giant dogs by providing the care necessary to protect them from their specific health issues.

The domestic dog has the most diverse body shape of any mammalian species, with selective breeding over many centuries creating hundreds of new distinct canine shapes and sizes. Giant breeds are generally considered to be breeds with an average bodyweight above 45kg, substantially higher than the 14.3kg average bodyweight across all purebred dogs in the UK. Twenty-nine breeds are recognised as being giant, including the well-known Irish Wolfhound, Great Dane and Saint Bernard breeds. Historically, these dogs were created to be giant to support specialised working roles, such as guarding or herding.

Today, their popularity and striking appearance mean they have remained consistently popular as companion dogs, despite rising ownership costs. While there is growing awareness of health concerns linked to some extreme canine body shapes such as flat faces and skin folds, there has been limited evidence to date assessing the overall health and lifespan of giant breeds.

The new research, led by the RVC’s VetCompass Programme, analysed anonymised veterinary records from 2.25 million dogs attending UK primary-care veterinary practices during 2019 to help address this information gap. From this population, researchers identified 28,345 giant dogs and examined their demographic data, disorder frequency and lifespan records. The study also involved a detailed manual review of clinical records from a random sample of more than 4,300 giant dogs to assess the most common health disorders and causes of death.

The most concerning finding was that the average lifespan of giant dogs was 8.9 years. This is more than three years shorter than the average lifespan previously reported within VetCompass for dogs overall in England. This aligns with research reported in many countries that more rapid growth in giant dogs leads to more rapid ageing.

The findings also showed that almost three-quarters (73.8%) of giant dogs had at least one disorder recorded annually, significantly higher than the average for all dog breeds (65.8%) within VetCompass. The most common general groups of disorders overall were skin disorders, musculoskeletal disease and ear disease. The most common specific diseases were ear infections (8.2%), overweight or obesity (8.0%) and aggression (5.6%). The frequency of aggression in these giant breeds was more than double the 2.2% level recorded in dogs overall and suggests owners should consider dog behaviour carefully when acquiring a giant breed dog.

Additional findings included:

• The most common giant dog breeds in the UK were the Dogue de Bordeaux, Alaskan Malamute and Akita.
• Female giant dogs lived 0.8 years longer on average than males (9.3 years compared to 8.5 years). So, acquiring a female giant breed dog could offer owners the possibility of a longer life for their new dog.
• Some giant breeds showed extremely short average lifespans, including Tibetan Mastiffs at just 4.8 years.
• Cancer was identified as the leading cause of death in giant dogs overall.
• Great Danes (60.5kg), Irish Wolfhounds (64.0kg) and Saint Bernards (65.1kg) were the heaviest of the 29 giant breeds recorded.

The combination of shorter lifespans and higher disease risk raises important welfare questions about the consequences of selecting dogs for highly exaggerated body size.

Professor Dan O’Neill, Professor of Companion Animal Epidemiology at the RVC and lead author of the paper, said: “Humanity has reshaped the domestic dog into the most physically diverse mammalian species on earth to create over 1,200 distinct dog breeds. Among these, the giant dog breeds can offer wonderful companionship for humans, but our findings suggest that the lifespan and welfare costs for these dogs, linked to their extreme body size, are substantial.”

“The relatively short lives of giant dogs compared to the wider dog population should prompt wider discussion on the welfare limits of selective breeding towards extreme giantism. To protect these cherished breeds and make them sustainable for the future, moving towards more moderate body sizes within these breeds may help to improve both the quality and length of life for these dogs, while still giving owners a fulfilling dog-ownership experience.”

Dr Julian Hoad, BSAVA Senior Vice President, said: “BSAVA welcomes this research, which adds to the growing evidence base needed to improve canine health and welfare. The veterinary profession remains concerned about the health consequences associated with extreme conformations and is committed to supporting reforms through research, education and evidence-based breeding practices.”