Brachycephalic Obstructive Airway Syndrome is an inherited condition affecting dogs and cats resulting in the abnormal development of the skull.

What is BOAS?

Brachycephalic Obstructive Airway Syndrome, also known as Bachycephalic Airway Syndrome, is an inherited condition affecting dogs and cats which results in the abnormal development of the skull.

Whilst the skull is a normal width, its length is significantly reduced. The soft tissues within the skull (e.g. the tongue and soft palate) are not reduced in size to compensate for this development, and so they end up taking up vital breathing space within the upper airways. The most common abnormalities associated with BOAS include, narrowed nostrils, narrowed windpipe, elongated soft palate and everted laryngeal saccules.

Without the right care and attention, these abnormalities can lead to severe breathing difficulties, overheating and exercise intolerance in pets. 

Why do these breeds have problems? 

BOAS is an inherited condition, and as the name suggests, BOAS affects mainly brachycephalic breeds. The term brachycephalic comes from the Greek meaning ‘short’ and ‘head’. Common breeds affected include Pugs, French Bulldogs, British Bulldogs, Cavalier King Charles Spaniel, Shih Tzu, Persians, Exotic and British Shorthair cats.

How will I know if my pet has Brachycephalic Obstructive Airway Syndrome

If you are concerned your pet is affected by BOAS, please don’t hesitate to talk to us for some advice. 

Some of the clinical signs you might notice at home, which are characteristic of this condition include snoring, noisy breathing (i.e. inspiratory stridour), difficulty breathing (i.e. dynpnoea), exercise intolerance, sleep apnoea and gastrointestinal disease (i.e. vomiting and regurgitation). Some of the primary abnormalities of the condition can be noted on visual inspection e.g. narrowed nostrils.

How is BOAS diagnosed?

There is no single diagnostic test for diagnosing BOAS in your pet. Diagnosis is based on findings from both a conscious examination, and an examination requiring a light plane of anaesthesia in order to examine the oral cavity in more detail. Patient signalment (e.g. breed) and history (e.g. clinical signs), also help towards diagnosis. A chest x-ray will allow us to assess the thickness of your pet's soft palate, and diameter of their trachea.

How can BOAS be treated? 

Depending on the severity of the condition at time of presentation, BOAS is a surgical disease. This is mainly due to the abnormalities which cause the condition being amenable to surgical correction e.g. the narrowed nostrils can be made wider, the elongated soft palate can be shortened etc. Some of the traits, e.g. narrowed windpipe, are not able to be corrected by surgical or medical management, and being aware of their presence mainly serves as a prognostic indicator.

The earlier the condition is diagnosed and treated, the better the outcome for your pet.

What is the prognosis?

Depending on the severity of the clinical signs, the prognosis is variable. Early intervention makes for a better prognosis. The longer the condition is allowed to develop and progress (i.e. the primary problems cause the eventual development of the secondary changes), the more invasive the treatment, and often, less favourable the long-term prognosis.

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