Brachycephalic Obstructive Airway (BOAS) Surgery
Brachy means shortened and cephalic means head. Therefore, brachycephalic dogs have skull bones that are shortened in length, giving the face and nose a pushed-in appearance.
Due to the shorter bones of the face and nose, the anatomy and relationship with the other soft tissue structures are altered; some of these changes can cause physical problems for the affected dog.
The most severely affected are, French Bulldogs, English Bulldogs and Pugs.
What Is Brachycephalic Airway Syndrome?
Brachycephalic airway syndrome refers to a particular set of upper airway abnormalities that affect brachycephalic dogs. This syndrome is also called brachycephalic respiratory syndrome, brachycephalic syndrome, or congenital obstructive upper airway disease.
The upper airway abnormalities that occur in this syndrome include:
Dogs with stenotic nares ( narrow nostrils) have abnormally narrowed or small nostrils; the narrowing restricts the amount of air that can flow into the nostrils.
EXTENDED NASAOPHARYNGEAL TURBINATES
Nasopharyngeal turbinates are ridges of bone covered by tissue that help humidify and warm air that is inhaled. When these extend past the nose into the pharynx (the area behind the nose and mouth), they cause variable amounts of airflow obstruction.
ELONGATED SOFT PALATE
A dog with an elongated soft palate (the soft part of the roof of the mouth) has a soft palate that is too long for the length of the mouth; the excess length partially blocks the entrance to the trachea (windpipe) at the back of the throat.
Laryngeal collapse is caused by the chronic stress placed on the cartilage of the larynx by other features of brachycephalic airway syndrome. Eventually, the larynx (voice box) is not able to open as wide as normal, causing further restriction in airflow.
A hypoplastic trachea means that the trachea has a smaller diameter than normal.
What Does BOAS Surgery Involve?
Surgery involves removing excess tissue causing obstruction along the airway, thereby widening the airway with the aim of relieving clinical signs.
Physical features that can be treated with surgery are elongation and thickening of the soft palate, blocked nostrils (narrow nostrils), and enlarged tonsils (enlarged tonsils).
THE SOFT PALATE
It is the loose piece of flesh that hangs down the back of the throat separating the oral cavity from the nasal cavity.
In brachycephalic breeds, it is longer and thicker and can block the trachea in episodes and stop breathing for a short time, while taking up more room in the throat, reducing space for airflow.
This structure is responsible for snoring.
Surgery to correct this involves cutting it to a more suitable length, as you often see in long-nosed breeds.
Common in some brachycephalic – especially pugs. Have you ever noticed that they puff out their chest when they inhale?
This growing effort is aimed at overcoming those narrow holes to optimize the amount of air they can use in each breath.
Surgery aims to remove excess nasal tissue to open the passage for airflow.
Usually seen after other airway problems. Over time, the tonsils enlarge and are pulled out of the sac due to the negative pressure created in the throat, which further increases the turbulent airflow.
The obstructing tonsils can be surgically removed.