Dynamic Airway Collapse Flashcards
Likely history of dynamic airway collapse?
- Exercise intolerance
- Noise at exercise
- (dogs tend to make a very marked noise and collapse, in the horse collapse is rarer, they tend to slow and then just stop)
Diagnostics for dynamic airway collapse?
- Physical examination
- Resting endoscopy
- Endoscopy at exercise
- Diagnostic imaging (sometimes)
What does rostral nasopharyngeal collapse cause?
- INSPIRATORY NOISE
- Causes minor problem
- Something rostral to the pharynx is blocking it
What is rostral nasopharyngeal collapse sometimes associated with?
- Occ associated with airway inflammation
- Treat this – Local/systemic anti-inflammatories -throat sprays
- Lymphoid hyperplasia
How does dorsal/lateral nasopharyngeal collapse present, and in what population of horses?
- Much more serious than rostral
- inspiratory noise
- 2-3 YO’s
- Also increasing in older WB dressage horses
What are the causes of dorsal/lateral nasopharyngeal collapse?
- Sensory or motor problems with muscles
- Inflammation/neuritis of IX and X (glossopharyngeal and vagus)
- Other systemic disease – gutteral pouch dx, primary muscle dx, nasal obstruction, LRT disease
What are the features of brachycephalic obstructive airway syndrome (BOAS)?
- Pharyngeal collapse (sometimes)
- Stenotic nares
- Excessively long soft palate
- Everted laryngeal saccules
What is dorsal displacement of the soft palate (DDSP)?
- Common, intermittent dynamic condition
- Must be diagnosed at exercise
- Performance limiting
- Their soft palate will displace, will slow/stop, swallow, breathe and then will be off again
What are the clinical signs of DDSP?
- Expiratory noise, ‘gurgling’ noise, swallow, open-mouth breathing
- Sometimes have an intermittent cough
How is DDSP diagnosed?
- History
- NOT resting endoscopy, UT we need to do resting endoscopy to make sure there are no other abnormalities that will predispose them to DDSP
- Dynamic endoscopy
Other differentials for DDSP?
- These may be concurrent
- Pulmonary dx
- Cardiac dx
- Lameness
- Neurological dx
Non-surgical options for management of DDSP?
- Treat underlying gutteral pouch disease/URT inflammation
- Re-assess horses once fit
- Alter tack to change head-position
- Dropped noseband
- Bitless bridle
- Throat support device (can only use for training, not events)
Which type of laryngeal hemiplegia (‘Roarers’/ Recurrent laryngeal neuropathy) is the most common and why?
- Left-sided
- The most common
- Loss of neurons in longer left recurrent laryngeal n (X)
- Poorly designed nerve, makes it one of the longest nerves in the body, and means that if you are going to get axonopathy type diseases it will occur here
What can cause right sided laryngeal hemiplegia (‘Roarers’/ Recurrent laryngeal neuropathy)?
- Often related to inflammation or direct damage to the right recurrent laryngeal nerve
- Can be due to trauma or poor venepuncture techniques
- Gutteral pouch mycosis
- Neck trauma/abscesses/neoplasia
What is bilateral laryngeal hemiplegia (‘Roarers’/ Recurrent laryngeal neuropathy) associated with?
- liver disease – unknown aetiology
- Pb toxicity
- OP toxicity
- CNS dx
How is laryngeal hemiplegia (‘Roarers’/ Recurrent laryngeal neuropathy) diagnosed?
- History
- Inspiratory noise
- Physical examination
- Endoscopy (resting)
- Treadmill/Overground endoscopy
- Ultrasonography
What can cause laryngeal hemiplegia in dogs?
- Large breed dogs
- Hereditary – Husky and husky X
- Labradors, GR, IS, Newfoundlands, St Bernards
- Concurrently with endocrine disorders incl hypothyroidism
- Head trauma/abscess/neoplasia
Clinical signs of epiglottic entrapment?
- Abnormal resp noise at rest and exercise
- May or may not be exercise intolerance
Diagnosis of epiglottic entrapment?
- Endoscopy (exercise endoscopy if intermittent, resting if permanent)
- Radiography – assess epiglottic size
Clinical signs of subepiglottic cysts?
- Resp noise, (+/-) exercise intolerance, coughing, dysphagia
- Smooth, pink, fluctuant, mucosal covered mass beneath epiglottis
- Not a dynamic disease but can cause DDSP
Diagnosis of subepiglottic cysts?
- Endoscopy- nasopharyngeal
- Endoscopy – oral
- Oral examination
Causes of dynamic tracheal collapse? (equine)
- Shetlands and miniature horses
- Secondary to peritracheal abscesses/tumours
- Cartilage trauma
- Cartilage malformation
- Often congenital
Clinical signs of tracheal collapse? (equine)
- Exercise intolerance, resp distress, stridor (‘goose-honk’)
- Some asymptomatic unless stressed
- Often doesn’t manifest until they start to develop lung disease
Diagnosis of tracheal collapse? (equine)
- Auscultation
- Palpation
- Exercise test
- Endoscopy (usually resting)
- Radiography
