Brachycephalic Obstructive Airway Syndrome (BOAS) is a result of many soft tissue factors directly related to design with shortened skull bone length . Various breeds are recognized as brachycephalic including Boston Terriers, Shih Tzus, Boxers, English and French bulldogs, Lhasa Apsos, Pekingese, Pugs and Shar Peis. It should be noted that not all brachycephalic breed dogs suffer from this syndrome. Bulldogs are usually the most severely affected.
The primary soft tissue abnormalities are stenotic nares and soft palate elongation. The secondary changes include eversion of the laryngeal saccules (Stage 1 laryngeal collapse), further elongation of the soft palate, tonsil enlargement, more advanced irreversible laryngeal collapse and often gastrointestinal symptoms. These changes can be halted by early surgical correction of the primary airway obstructive problems. Stenotic nares may be the only issue that needs correction.
Stenotic nares is a congenital abnormality where the nostril diameter is diminished and therefore reduces airflow as the pet breathes. BAS is a progressive disease and the best treatment is an early treatment. Air passage through the nasal cavities accounts for approximately 75 % of total airflow resistance in dogs. It is a known fact that a 50 % reduction in tube radius (the narrow nasal opening ) leads to a 16 fold increase in resistance to air flow. (Poiseuille’s Law)
BOAS individuals may have laboured breathing example, snorting, noisy breathing, gagging etc….. as they struggle to obtain sufficient oxygen. The reason this occurs is due to the excessive negative pressure that occurs with every breath they take. With their airway pathway being reduced, the individual exerts this negative pressure during inspiration in attempt to maintain air flow which distorts the pharyngeal tissue. This results in a vicious cycle of more tissue stretching, swelling and more severe laryngeal collapse. It just goes from bad to worse!
Here are two recent surgical cases that have been performed at our Mississauga hospital that have greatly benefited from early corrective upperairway surgery! In the majority of cases once corrective surgery has been performed, the dog has carefree, effortless breathing with a much more active, healthier lifestyle.
1) Wyatt is a male, neutered, English Bulldog, who had BOAS surgery when he was 7 months old.
Structural findings were as follows: (All these features are visible in the photos)
+severe stenotic nares ( surgical correction)
+laryneal saccule evertion/Stage 1 Collapse ( surgical correction)
+Inwards position of the aryepiglottic folds/Stage 11 Collapse)
+normal length to soft palate with a deformed shortening on the left side.
- A view of Wyatt’s Larynx during surgery
Wyatt’s photo clearly demonstrates that his good looks will forever be adorned.
2) Oliver is a male, neutered, French Bulldog, who had BOAS surgery when he was 5 months old.
Structural findings were as follows:
+severe stenotic nares (surgical correction)
+laryngeal saccule evertion (surgical correction)
+enlarged tonsils (common)
+normal length soft palate
In this photo Oliver’s nose has completely re-established pigmentation 2 months later.
It is expected that both these pets will do very well in life now that corrective surgery has created a good airway!
Time does fly when every day counts. Both these dogs have maximum activity and ability to breath-September 2017
1) Owners always comment that after surgery as in the case of Wyatt and Oliver smelling everything is a new found gift.
2) People always say that they are surprised that their dog doesn’t make any noise when he/she breathes.
Pleased note that these advanced airway surgeries are done at both our animal hospitals in Mississauga and Oakville.
Our health care team at Southdown Animal Clinic in cooperation with Wyatt and Oliver and their respective parents are proud to share their success stories.
Fr Bulldog : My name is Mason
Fr Bulldog : My name is Brock, I am Mason’s brother and we both had stenotic nares surgery (BOAS) the same day.
Shih Tzu: My name is Leo
Pre and post surgical appearance of stenotic nares surgery