Respiratory Moderate to Severe Hereditary DogCat

Brachycephalic Airway Syndrome

Also known as: BAS, Brachycephalic Obstructive Airway Syndrome, BOAS

Brachycephalic Airway Syndrome (BAS) is a set of upper airway abnormalities found in short-nosed (brachycephalic) breeds. The syndrome includes stenotic nares (narrowed nostrils), elongated soft palate, hypoplastic trachea, and everted laryngeal saccules. These anatomical abnormalities create increased airway resistance and respiratory compromise.

Symptoms & Signs

Causes & Risk Factors

Selective breeding for extreme brachycephalic skull conformation. The shortened skull compresses soft tissue structures into a reduced space, creating multiple levels of airway obstruction. Secondary changes (laryngeal collapse, tracheal hypoplasia) develop over time due to chronic negative pressure.

Diagnosis

Physical examination revealing characteristic breathing patterns. Laryngoscopy under light sedation to evaluate soft palate length and laryngeal function. CT scanning for comprehensive airway assessment. Grading systems (Cambridge BOAS grading) quantify severity.

Treatment

Surgical correction: stenotic nares resection (rhinoplasty), staphylectomy (soft palate shortening), laryngeal sacculectomy. Weight management is critical. Avoid heat and excessive exercise. Emergency management of acute respiratory distress.

Prevention

Breeding for moderate skull conformation. Functional breeding assessments (exercise tolerance testing). Avoiding breeding of severely affected individuals. Public education about brachycephalic health issues.

Prognosis

Good with early surgical intervention. Surgery significantly improves quality of life and exercise tolerance. Without treatment, progressive airway deterioration occurs. Laryngeal collapse carries a poorer prognosis.

Affected Breeds (6)

BreedSpeciesSize
Exotic ShorthairCatMedium
HimalayanCatMedium
PersianCatMedium
Brussels GriffonDogToy
BulldogDogMedium
PugDogSmall

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