BOAS

Brachycephalic Obstructive Airway Syndrome

What is BOAS?

The shape of the head and muzzle of some breeds of dog means they have reduced tolerance to exercise as they face difficulties breathing. Such animals are labelled as ‘brachycephalic’, meaning “short headed”. Breeds that are commonly affected include: English and French Bulldogs, Pugs, Shih-Tzus, and Pekingese. Animals that are brachycephalic are at risk of developing BOAS, Brachycephalic Obstructive Airway Syndrome, which can present signs such as:

Stenotic nares

(very narrow nostrils)

Elongated soft palate

(inside mouth between the entrance to trachea and oesophagus)

Everted laryngeal saccules

(tissue around larynx inside mouth)

These three conditions combined (or often just one of these conditions) can significantly impair a dog’s ability to breathe properly. Affected dogs can also suffer from a narrow trachea, laryngeal collapse, laryngeal paralysis, or hiatal hernia (when part of the stomach slides into the chest).

What are the symptoms of BOAS that owners should look out for?

Noisy breathing is the most common sign of BOAS. Owners need to be on the lookout for this as noisy breathing is absolutely and definitely NOT normal for any dog. If your English or French Bulldog, Pug, Shih-Tzu or Pekingese cannot sustain deep, noise-free breaths when at rest or during gentle exercise, this is cause for concern and you should get a referral to our surgical team for a BOAS assessment.

If an affected dog is stressed or worried, is in pain, gets too hot or is just exercised more than usual, the risks of inadequate ventilation are high and the consequences can be extremely uncomfortable and even life-threatening for the dog.

Coughing and vomiting in a brachycephalic dog can increase the risk of aspiration pneumonia (infection caused by inhaling food or vomit). Aspiration pneumonia is a severe condition that along with obesity, further lowers your dog’s tolerance for limited breathing.

Sleep apnoea (prolonged time between breaths during deep sleep) can also be dangerous and is another indicator of a BOAS issue.

How do we diagnose and then assess BOAS?

Stenotic nares (very narrow nostrils) can be observed easily during a clinical examination. If we want to assess the soft palate and laryngeal saccules, your dog will need a general anaesthetic. For us to examine the trachea and check for a hernia, we use our endoscopy equipment.

Respiratory Function Grading Scheme

If BOAS is suspected, then we grade its severity using the ‘Respiratory Function Grading Scheme’. This is a BOAS specific protocol designed by the Kennel Club (KC) and the University of Cambridge. The Respiratory Function Grading Scheme assesses Bulldogs, French Bulldogs, and Pugs for BOAS, advising owners of the extent to which their dog is affected by BOAS and giving guidance on breeding. Our veterinary surgeons, Katie & Emma, are Kennel Club approved RFGS Assessors for the region. If you would like a BOAS assessment then your dog should be:

If your dog is KC registered, please bring your documents to the assessment. To book a BOAS assessment please contact us or if you are a vet, please complete the referral form on our referrals page.

What treatment can we provide for BOAS?

BOAS abnormalities should be treated to increase the comfort of the affected dog. These are not cosmetic changes; they can make a big difference for a patient who cannot otherwise enjoy sunny weather or a run in the park.

Treatment for BOAS is always done under general anaesthetic at our Crawley branch. Once anaesthetised:

We assess with an endoscope to make sure no other issues are present.
We take an x-ray to measure the diameter of the trachea (windpipe).
We can then assess and surgically shorten the soft palate, so that it doesn't obstruct the entrance to the airways (soft palate reduction).
We can also correct the nares (very narrow nostrils) by surgically widening them, which results in immediate increase in air flow (rhinoplasty).
Finally, we can surgically remove everted laryngeal saccules (laryngeal saccule removal).