Collapsing Trachea
- Occurs principally in
- Horses - small ponies
- Dogs - miniature and toy breeds eg: miniature Yorkshire terriers
- Also cattle and goats
- Degeneration of tracheal ring cartilage and replacement with fibrous tissue results in reduced tracheal ring stiffness
- Flattening of the trachea dorsoventrally and widening of the dorsal membrane results in reduced airway diameter
- Airway diameter is further reduced by thickening of the dorsal membrane
- The dorsal membrane can become thickened with repeated low grade trauma/chronic tracheitis
- Can be segmental and extrathoracic or intrathoracic
- Extrathoracic collapse:
- Inspiratory dyspnoea
- Dorsal membrane prolapses into the lumen on inspiration, bulges out on expiration
- Intrathoracic collapse
- Expiratory dyspnoea
- Dorsal membrane prolapses into the lumen on expiration, bulges out on inspiration
- Some dogs exhibit a characteristic "goose-honk" cough