What is BOAS?
BOAS stands for Brachycephalic Obstructive Airway Syndrome. Quite the mouthful. This syndrome affects brachycephalics; that is to say, our flat-faced friends such as the French Bulldog, Pug, British Bulldog, and Pekingese, among others.
BOAS is a result of extreme selective-breeding of dogs for as short-a-snout as possible. The question arises – why have people been breeding dogs with shorter and shorter snouts, and flatter and flatter faces? The researcher Konrad Lorenz (yes, the one who became a ‘mother’ to a gaggle of geese), coined the term “Kinderschema” to describe how infant-like features such as large, wide set eyes and a flat, round face elicit an innate parenting and nurturing response in people. The French Bulldog can attribute its immense growth in popularity to its rounded face, button-nose and puppy-dog eyes; indeed, it so perfectly encapsulates “Kinderschema”, that it is set to overtake Labradors in numbers in the UK, according to the Kennel Club. Brachycephalics are generally sweet-natured dogs who we find cute, so why would there be any need to write an article about anything other than the finest moments of Doug the Pug? Why did the President of the British Veterinary Association contact the organisers of Comic Relief, encouraging them not to use images of “Albert”, the French bulldog used in a Red Nose Day campaign?
The reason is, of course, BOAS. This condition causes laboured breathing, exercise intolerance and can drastically decrease the quality of life of these dogs. This welfare issue arises as a result of extreme selective breeding; let us explore some of the negative anatomical components of having such a flat face…
- Stenotic nares. The selective breeding of breeds for a flat face has led to narrowed nares (the nostrils). Consequently, it is harder for the animal to inhale and exhale freely, as there is so much resistance to airflow in these narrow “tube” openings.
- Elongated soft palate. The skull of brachycephalics has been greatly shortened by selective breeding; however, there hasn’t been the same corresponding shortening of soft tissues. Consequently, the soft palate (of the roof of the mouth) is often too long for the short skull, and hangs over the entrance of the airways to the trachea, leading to snorting and struggling to breathe.
- Tracheal hypoplasia. This means a smaller-than-normal windpipe, which causes increased resistance to airflow, making inspiration difficult.
The effects of these features results in increased “turbulence” of airflow; this leads to issues because of damage to the supportive cartilage, including:
- Laryngeal collapse. The cartilaginous support of the larynx (voice-box) is not strong enough to cope with the turbulent airflow, and so often collapses, causing severe respiratory distress (inability to breathe).
- Snoring and This isn’t cute – it’s because they’re starting to choke!
- Exercise intolerance. The high resistance and turbulence of airflow in the windpipe and nose results in difficulty getting sufficient air into the lungs. When the dog exerts themselves, they may temporarily suffocate and
- Everted tonsils. There is a lot of pressure sucking on the tonsils, created by the strain to inhale. This can cause them to become enlarged, forming further obstruction of the
Dogs with BOAS may see clinical signs in other body systems, too, not just the airways:
- Heart disease.
- Acid reflux and stomach
So, there are plenty of reasons to be concerned about BOAS, but don’t worry, help is at hand!
I’ve got a pug – does he have BOAS?
Although BOAS is common in these flat-faced dogs, with a study by Cambridge University revealing up to 60% of pugs were affected, not every single brachycephalic will suffer from BOAS. A number of examinations are needed to show the condition is causing issues:
- Clinical signs and history; if you have noticed your dog snoring, snorting, struggling to breathe or struggling to exercise, it is important to let us know.
- Examination of the nares; unfortunately, this cannot be done purely by a visual inspection, and requires investigations deeper up the nose.
- X-rays; of the head and chest (to assess the windpipe and heart).
- Airway examination; by laryngoscopy (looking at the larynx) or
What can be done?
If your dog is diagnosed with BOAS, there are a number of potential solutions to improve his quality of life.
- Surgical treatment:
- Widening the
- Shortening the soft
- Removal of excess laryngeal tissue in laryngeal
- Removal of the
- Medical treatment:
- Medication of gastric
- Medical management of heart
- Lifestyle changes:
- Weight management; obese animals are particularly susceptible, so shedding a few pounds would be no bad thing for his respiratory health!
- Preventing overheating and heat-
What is the prognosis?
Every dog is different. Prognosis depends upon the degree of disease prior to intervention, and the intervention itself. However, when the resistance in the airways is decreased by widening nostrils and removing pesky excess tissues, the turbulence in the airways will greatly decrease, too. This means that the secondary issues discussed earlier will become less of a problem, and you will see an increased quality of life in your pet!
Wishing you and your flat-faced friend a very happy summer from all of us!
“Flo: She’s burning up a fever, Charlie. She could have pneumonia!
Charlie the German Shepherd: Think she needs a vet?
Flo: Charlie, she’s a little girl. She needs a doctor.”
– All Dogs Go to Heaven.