12 Dog Breeds Face Breathing Risks, Study Finds

Researchers identify high-risk breeds like Pekingese and Japanese Chin for Brachycephalic Obstructive Airway Syndrome.

Published on Feb. 24, 2026

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A new study from the Cambridge Veterinary School has identified 12 out of 14 dog breeds as being at risk of Brachycephalic Obstructive Airway Syndrome (BOAS), a serious breathing condition affecting flat-faced or short-skulled dogs. The Pekingese and Japanese Chin were found to have the highest rates of BOAS, comparable to the French Bulldog, Pug, and Bulldog. Several other breeds, including the Shih Tzu, Griffon Bruxellois, and Boston Terrier, were also identified as moderate to high risk.

Why it matters

BOAS can significantly reduce a dog's quality of life, leading to noisy breathing, exercise intolerance, and difficulty coping with heat and stress. While treatments exist, the condition is hereditary, so understanding breed-specific risk factors is crucial for breeders and owners to improve the health and welfare of these dogs going forward.

The details

The study, published in PLOS One, involved assessing nearly 900 dogs across 14 brachycephalic breeds. Researchers found that factors like a wider, shorter head shape, narrowed nostrils, shorter tails, and thicker necks were all associated with increased BOAS risk in certain breeds. Being overweight was also a significant risk factor for some breeds like the Cavalier King Charles Spaniel, Shih Tzu, and Affenpinscher.

  • The study was published on February 19, 2026.

The players

Fran Tomlinson

A co-lead researcher on the study from the Cambridge Veterinary School.

David Sargan

A researcher who contributed to the study from the Cambridge Veterinary School.

Jane Ladlow

A co-lead researcher on the study from the Cambridge Veterinary School.

Pekingese

A dog breed found to have an 89% rate of BOAS, one of the highest among the breeds studied.

Japanese Chin

A dog breed found to have an 82% rate of BOAS, also one of the highest among the breeds studied.

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What they’re saying

“BOAS exists on a spectrum. Some dogs are only mildly affected, but for those at the more severe end, it can significantly reduce quality of life and become a serious welfare issue.”

— Fran Tomlinson, Co-lead researcher (PLOS One)

“Our findings show that the relationship between relative muzzle length and BOAS risk is more complex than is commonly assumed.”

— David Sargan, Researcher (PLOS One)

“Considering the close genetic relationship between Staffordshire Bull Terriers, Boston Terriers and the bulldogs, it isn't surprising that they share this link between neck thickness and BOAS.”

— Jane Ladlow, Co-lead researcher (PLOS One)

What’s next

The researchers hope this study will lead to more flat-faced dogs being tested for BOAS and encourage greater engagement on this issue among breeders, owners, and judges to select for features that are less detrimental to dog health.

The takeaway

This study highlights the complex, breed-specific nature of BOAS risk factors, underscoring the need for a tailored approach to addressing this serious breathing condition across different brachycephalic dog breeds.