Brachycephalic Syndrome

brachycephalic Dogs & boas

Brachycephalic Obstructive Airway Syndrome (BOAS)

This syndrome is common in breeds like English Bulldogs, French Bulldogs, Pugs, and Boston Terriers.

French Bulldog Sitting


Brachycephaly, meaning “short head,” is common in breeds like English Bulldogs, French Bulldogs, Pugs, and Boston Terriers. This condition can lead to brachycephalic obstructive airway syndrome (BOAS), where anatomical features cause increased resistance or obstruction when breathing. 


Brachycephalic dogs have a shortened skull, resulting in a compressed nose and abnormal throat anatomy. Compressed/abnormal anatomy may include: 

  • Narrowed nostrils
  • Redundant turbinates in the nose
  • Elongated/thickened soft palate
  • Large tongue
  • Narrowed windpipe

Abnormal airway anatomy in BOAS dogs causes breathing issues, leading to swelling, tissue deformation, and obstruction. They may snore loudly, with worse symptoms when excited, exercising, or hot. 

Signs of breathing effort include: 

  • Flaring of nostrils
  • Curling of tongue
  • Wide open mouth
  • Use of abdominal muscles and diaphragm
  • Fast breaths
  • Blue colored gums or tongue
  • Collapse


Dogs cool themselves by panting, but brachycephalic dogs may struggle with this, especially under stress or anxiety. Signs of overheating include drooling and heavy panting. 


Brachycephalic dogs may vomit or regurgitate due to breathing efforts, sometimes caused by gastroesophageal reflux (GERD) or a diaphragmatic hernia, increasing pneumonia risk. Notify your veterinarian if your dog shows these symptoms. 


Brachycephalic dogs can be hard to restrain or examine due to breathing issues from stress. Aggressive dogs or those that bark or bite are particularly problematic. We sometimes sedate them or ask family members to assist with routine procedures to reduce stress. 


Brachycephalic dogs are more likely to have complications during sedation and with general anesthesia. Our anesthesia team carefully monitors these procedures to ensure good outcomes. Many owners travel to have a board-certified anesthesiologist present to minimize risks. 


Owners of brachycephalic dogs should monitor them during exercise, heat, and stress like when obtaining veterinary care. Keep them fit with a lower body condition score, use a harness instead of a neck lead, and limit exercise in hot weather. Pre-emptive sedatives and feeding from an elevated surface can also help. 

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