Brachycephalic Obstructive Airway Syndrome
What is Brachycephalic Obstructive Airway Syndrome (BOAS)?
Brachycephalic Obstructive Airway Syndrome commonly known as ‘BOAS’ is a breed-related condition affecting the airways of “squished” faced breeds. Breeds commonly affected by BOAS include French Bulldogs, Australian Bulldogs, English Bulldogs, Shih Tzus, Pekingese, Boxers, Pugs, Cavalier King Charles Spaniels, Boston Terriers, Brucels Griffon, Llasa Apso amongst others.
BOAS affected breeds have difficulty breathing in air due to the narrowing of the upper airways. By attempting to breath more air in there is an increase in intrathoracic pressure contributing to further physical traumatisation of the upper airways, voice box, windpipe and stomach. This irritation and trauma can also cause increased salivation and mucous production which can become foamy, making the act of breathing even more difficult. The negative pressure can cause gastric reflux, aspiration pneumonia, hiatal hernias, upset gastro biome and other clinical signs.
Video: DR Andres Townsend explains BOAS in further detail
Characteristics of BOAS
The main congenital defects which characterise BOAS include:
- Stenotic nares: Narrow, “pinched” nostrils.
- Elongated and thickened soft palate: An unusually long soft palate that extends into the entrance of the larynx (voice box), reducing the amount of airflow, often resulting in snorting sounds.
- Caudal aberrant turbinates: The small bony structures within the nose (turbinates) extend too far beyond the nasal passage inhibiting normal airflow.
- Hypoplastic trachea: Narrowed, malformed, voice box and windpipe.
- Everted laryngeal saccules: Where part of the larynx itself obstructs airflow.
- Enlarged tonsils contribute to further reduction in airflow diameter.
- Enlarged tongue (macroglossia): Selective breeding for the “flat faced” appearance often results in a tongue that is too big for the skull, creating an obstructive barrier for airflow.
Signs of BOAS
Some of the common signs of BOAS include:
- Loud breathing, snorting or snoring.
- High pitched noises similar to wheezing.
- Poor quality sleep/sleep apnea where the patient seems to choke as they fall asleep causing them to frequently wake up.
- Preference to or involuntarily sleeping while sitting up.
- Stress and an inability to exercise normally (exercise intolerance).
- Gastrointestinal signs such as vomiting, gagging, excessive salivation and reflux.
- Sensitivity to heat including being prone to heat stroke, dehydration, rapid heart rate and sudden collapse.
Diagnosis and Correction
The airway abnormalities caused by this condition can be extremely serious, sometimes even life-threatening and should be corrected with surgery so that your pet can live a healthy, happy life. To reduce progression of disease and to reduce the risk of complications arising from surgery, we advise that surgery be performed as early as clinical signs are detected.
There are multiple surgical options available depending on the specific BOAS characteristics your pet displays. These include:
- Surgery to trim the nostrils and in turn widen them to allow better airflow.
- Surgery to trim the abnormally elongated/thickened soft palate.
- Surgery to trim the laryngeal saccules which block the windpipe.
- Surgery to remove enlarged tonsils.
See the incredible results achieved from a nostril surgery in the following before and after image.
If your pet displays any of the above-mentioned signs or if you have one of the breeds commonly affected by this condition and would like to rule out any issues, please contact us to book them in for a veterinary assessment with one of our vets. Our veterinarians will assess your dog’s individual degree and severity of BOAS and determine which airway components require surgical correction.