Brachycephalic obstructive airway syndrome

Bulldog portrait Frank

Brachycephalic obstructive airway syndrome (BOAS) is a pathological condition affecting short-nosed (brachycephalic) dog breeds. This syndrome is characterized by a combination of anatomical abnormalities that lead to significant respiratory distress.

Anatomy and Pathophysiology

BOAS is primarily seen in brachycephalic breeds such as Bulldogs, Pugs, and Boxers. The condition arises due to the shortened bones of the skull, which result in a compressed upper respiratory tract. Key anatomical features contributing to BOAS include:

• Stenotic nares: Narrowed nostrils that restrict airflow.
• Elongated soft palate: Excessively long soft palate that obstructs the airway.
• Hypoplastic trachea: Underdeveloped trachea that is narrower than normal.
• Everted laryngeal saccules: Tissue inside the larynx that can become everted and obstruct the airway.

Clinical Signs

Dogs with BOAS often exhibit a range of clinical signs, including:

• Dyspnea: Difficulty breathing, especially during exercise or in hot weather.
• Stridor: High-pitched, wheezing sound during breathing.
• Cyanosis: Bluish discoloration of the skin and mucous membranes due to lack of oxygen.
• Exercise intolerance: Reduced ability to perform physical activities.
• Snoring: Loud breathing sounds during sleep.

Diagnosis

Diagnosis of BOAS typically involves a combination of physical examination, medical history, and diagnostic imaging such as radiography or computed tomography (CT) scans. Endoscopy may also be used to visualize the internal structures of the airway.

Treatment

Treatment options for BOAS vary depending on the severity of the condition. Mild cases may be managed with lifestyle modifications, such as weight management and avoiding heat stress. Severe cases often require surgical intervention, which may include:

• Stenotic nares resection: Surgery to widen the nostrils.
• Soft palate resection: Trimming the elongated soft palate.
• Laryngeal sacculectomy: Removal of everted laryngeal saccules.

Prognosis

The prognosis for dogs with BOAS varies. With appropriate management and surgical intervention, many dogs experience significant improvement in their quality of life. However, the condition can be progressive, and ongoing monitoring and care are essential.

Prevention

Preventive measures include responsible breeding practices to avoid extreme brachycephalic traits and educating potential dog owners about the risks associated with brachycephalic breeds.

See also

• Brachycephaly
• Respiratory disease in dogs
• Veterinary surgery