New research reveals that a far wider range of dog breeds than previously understood are at high risk of developing severe breathing problems. The findings underscore a growing crisis in canine health linked to selective breeding for exaggerated physical traits, particularly in breeds with shortened snouts and flattened faces – known as brachycephalic breeds.
The Expanding List of At-Risk Breeds
For years, English bulldogs, French bulldogs, and pugs have been the primary focus of concern regarding brachycephalic obstructive airway syndrome (BOAS). This condition causes labored breathing, exercise intolerance, and difficulty regulating body temperature. However, a recent study led by Francesca Tomlinson at the University of Cambridge examined 898 dogs across 14 breeds to determine the true scope of the problem.
The study included affenpinschers, Boston terriers, boxers, cavalier King Charles spaniels, Chihuahuas, Dogue de Bordeaux, Griffon Bruxellois, Japanese chins, Maltese, Pekingese, King Charles spaniels, Pomeranians, shih tzus, and Staffordshire bull terriers. The results were alarming:
- Pekingese and Japanese chins exhibited the highest risk, with over 80% of dogs affected.
- Five breeds (cavalier King Charles spaniel, shih tzu, Griffon Bruxellois, Boston terrier, and Dogue de Bordeaux) showed a moderate risk, with BOAS affecting 50–75% of dogs.
- Maltese and Pomeranians were the only breeds where no clinically significant cases were found.
Why This Matters: The Impact of Extreme Breeding
The surge in popularity of these breeds over the last several years has directly correlated with a rise in severe health issues. Breeders prioritizing aesthetic traits over physiological function have created dogs prone to chronic suffering.
The study identified three main factors contributing to breathing disorders: obesity, narrowed nostrils, and extreme facial flatness. However, other traits—such as excessively short or curled tails—may also play a role in anatomical changes that exacerbate BOAS.
This isn’t simply about “flat faces” alone; it’s about the cumulative effect of exaggerated features selected for in breeding programs. The findings emphasize that selective breeding isn’t just about genetics but also about functional consequences.
What Owners and Breeders Should Do
Experts urge prospective owners to prioritize health over appearance. Look for breeders who conduct thorough health testing on parent dogs and educate yourselves on the potential implications of extreme physical traits.
As Anna Quain from the University of Sydney points out, breeding flat-faced dogs is akin to “designing a car without a radiator.” The goal should be welfare first, rather than perpetuating human preferences at the expense of animal health.
Breeders should focus on selecting against extreme features, as even minor adjustments can reduce disease risk. Paul McGreevy from the University of Sydney notes that breed labels are irrelevant when it comes to airway compromise. The real issue is the degree of physical exaggeration.
While some aspects of the study’s methodology have been questioned, particularly regarding the subjectivity of respiratory sound grading, researchers maintain that standardized protocols and objective criteria are used to ensure consistency. The goal of exertion tests isn’t athletic performance but assessing how the airway responds under mild stress.
The core message is clear: prioritizing function over extreme appearance is crucial for reducing suffering in brachycephalic breeds. Owners, breeders, and the veterinary community must collaborate to address this growing health crisis.
