BOAS Testing: What Every Brachycephalic Pet Owner Needs to Know Before Flying

What Is BOAS?

BOAS stands for Brachycephalic Obstructive Airway Syndrome — a condition that affects flat-faced (brachycephalic) breeds of dogs and cats. Breeds like French Bulldogs, English Bulldogs, Pugs, Boston Terriers, Shih Tzus, Boxers, Persian cats and British Shorthairs are all considered brachycephalic.

The condition arises from the physical structure of these animals' skulls. Their shortened facial bones compress the soft tissue within, leading to narrowed nostrils, an elongated soft palate, and a narrowed trachea. The result is restricted airflow — and in stressful or hot conditions, this can become life-threatening.

Why Does It Matter for Air Travel?

Commercial airlines have largely banned brachycephalic breeds from travelling in cargo holds — and for good reason. The combination of heat, stress and limited airflow in a cargo environment poses a serious and documented risk to these animals. Many airlines have also restricted them from the cabin entirely.

Even in a controlled, in-cabin environment like a SKYE PETS flight, it is essential that your pet's airway health is assessed before travel. A long-haul international journey — even in the most comfortable conditions — introduces stress, altitude changes and a shift in routine that can exacerbate underlying airway issues.

What Is BOAS Testing?

BOAS testing is a veterinary assessment that evaluates the severity of airway obstruction in brachycephalic animals. It typically involves:

• Resting respiratory rate monitoring — measured at home over several nights
• Exercise tolerance testing — a short walk or treadmill assessment to observe breathing under mild exertion
• Endoscopic examination — a more detailed internal assessment of the airway, conducted under sedation
• Whole-body barometric plethysmography (WBBP) — the gold standard non-invasive test, used at specialist centres to objectively grade airway function

The outcome of BOAS testing places your pet into one of three grades:

• Grade 0: Clinically unaffected — fit to fly
• Grade 1: Mildly affected — generally fit to fly with veterinary clearance
• Grade 2: Moderately affected — further assessment or corrective surgery recommended before travel
• Grade 3: Severely affected — not fit to fly

Which Breeds Should Be Tested?

Any dog or cat with a visibly flattened face should be assessed before international travel. Common breeds that require BOAS evaluation include:

• French Bulldog
• English Bulldog
• Pug
• Boston Terrier
• Boxer
• Shih Tzu
• Cavalier King Charles Spaniel
• Chow Chow
• Persian Cat
• British Shorthair
• Exotic Shorthair
• Scottish Fold

When Should Testing Happen?

Ideally, BOAS testing should be completed at least 3–6 months before your intended flight date. This gives time to:

• Receive a full assessment and grading
• Undergo corrective surgery if recommended (and allow full recovery time)
• Obtain the relevant veterinary health certificates and fitness-to-fly documentation
• Meet any destination country's specific health requirements

Some countries — including the UK and Australia — require specific health certificates that must be completed within a defined window before travel. Your BOAS test results may form part of this documentation.

Can Surgery Help?

Yes. For Grade 2 animals, corrective BOAS surgery — which may include widening the nostrils (nares resection), shortening the soft palate, and removing everted laryngeal saccules — can significantly improve airway function and quality of life. Many pets who undergo corrective surgery are subsequently cleared to travel.

It is strongly recommended that surgery be performed by a specialist veterinary surgeon with experience in brachycephalic breeds, and that full recovery (typically 8–12 weeks) is completed before travel.

What Does SKYE PETS Require?

At SKYE PETS, the safety and comfort of every animal on board is our highest priority. For all brachycephalic breeds, we require:

• A veterinary health certificate confirming fitness to fly, issued within the required timeframe for your destination
• Disclosure of any diagnosed BOAS grading at the time of booking
• For Grade 2 animals: evidence of specialist assessment and, where recommended, completed corrective surgery

Our team reviews every booking individually. If you are unsure whether your pet meets the requirements, we encourage you to reach out before booking so we can advise you properly.

Finding a BOAS Specialist

BOAS testing is available through specialist veterinary referral centres in Australia, New Zealand, the United Kingdom, Singapore and most major countries. Your general practice vet can provide a referral, or you can contact us and we will do our best to point you toward a trusted specialist in your region.

"The most important thing you can do for a flat-faced breed before any international journey is get them assessed early. BOAS is not a barrier to travel for most dogs — but identifying it early gives you options."

Summary

BOAS testing is a straightforward but critical step for any brachycephalic pet owner planning international travel. It protects your animal, gives you peace of mind, and ensures that your journey — however far — begins on the safest possible footing.

If you have questions about flying with a brachycephalic breed, our team is here to help. Get in touch or explore our current routes.