The Royal Veterinary College has announced the results of the world's largest study of West Highland White Terriers1, which identified both the most common illnesses suffered by the breed and the most common causes of death.

The VetCompass study, which was based on the records of over 900,000 Westies under the care of UK first opinion veterinary practices in 2016, also found that ownership of Westies has fallen dramatically, to just a quarter of what it was a decade ago. Researchers found that the breed comprised only 0.43% of puppies born in 2015 compared to 1.69% of puppies born in 2004.

The average age of the Westies studied was a relatively elderly 7.8 years, suggesting an ageing population with fewer new puppies entering the population compared to other breed studies carried out by VetCompass.

The most common illnesses suffered by Westies were found to be dental disease (which affects 15.7% of Westies), ear disease (10.6%), overgrown nails (7.2%), allergic skin disorder (6.5%) and obesity (6.1%). Lower respiratory tract disease and cancer were the most common causes of death, with each accounting for 10.2% of deaths in the breed. Spinal cord disorders were the next biggest killer at 7.8%.

Other findings included: 

  • Male Westies are more likely to be diagnosed with ear disease and aggression than female Westies.
  • Female Westies are more likely, however, to develop dental disease.
  • The average bodyweight of the Westie is 9.6kg, with males tending to be heavier with an average weight of 10.1kg compared to the 9.0kg average of females.
  • The average lifespan of the breed is 13.4 years with males outliving females at 13.8 years compared to the latter’s 12.9 years.

Dr Dan O’Neill, Senior Lecturer and VetCompass researcher at the RVC, who was the main author of the paper, said: "With the ascent of social media as a dominant influencer of public opinion, ownership preferences for dog breeds are becoming increasingly polarised and susceptible to the whims of internet celebrity endorsement and advertising.

"Previously, preferences for dog breeds used to wax and wane gently over time. But VetCompass breed data now show rapid changes in preferences among breeds that create bubbles and troughs of demand that can have far-reaching implications for these breeds.

"Flat-faced (brachycephalic) breeds are currently the darling of the nation but this has created huge welfare problems for breeds such as the Pug and French Bulldog. And breeds such as the West Highland White Terrier and Cavalier King Charles have fallen sharply out of favour."

Camilla Pegram, Veterinary Epidemiologist and VetCompass researcher at the RVC, who co-authored the paper, said: "The most common disorders of Westies shown in this study are also common in the wider UK dog population. However, the breed does seem predisposed to lower respiratory tract disease which was a common cause of death in the Westie. Owners should be aware of this as their Westie ages.

"What is particularly interesting is the level of skin disorders, which although relatively high, are still lower than might have been predicted a decade ago. It is possible that the reduction in Westie ownership has relieved the pressure on breeders to breed from less healthy individuals to meet demand and therefore contributed to improved skin health within the breed. Paradoxically, reducing popularity may have led to better health in the Westies that are now being born."


  1. O'NEILL, D. G., BALLANTYNE, Z. F., HENDRICKS, A., CHURCH, D. B., BRODBELT, D. C. & PEGRAM, C. 2019. West Highland White Terriers under primary veterinary care in the UK in 2016: demography, mortality and disorders. Canine Genetics and Epidemiology.

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