Brachycephalic Airway Syndrome
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
- Noisy breathing (stertor and stridor)
- Snoring
- Exercise intolerance
- Heat intolerance
- Cyanosis (blue gums) with exertion
- Gagging and retching
- Sleep apnea
- Collapse during exercise or excitement
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)
| Breed | Species | Size |
|---|---|---|
| Exotic Shorthair | Cat | Medium |
| Himalayan | Cat | Medium |
| Persian | Cat | Medium |
| Brussels Griffon | Dog | Toy |
| Bulldog | Dog | Medium |
| Pug | Dog | Small |