Dynamic Airway Collapse

Question 1

Likely history of dynamic airway collapse?

Answer 1

• 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)

Question 2

Diagnostics for dynamic airway collapse?

Answer 2

• Physical examination
• Resting endoscopy
• Endoscopy at exercise
• Diagnostic imaging (sometimes)

Question 3

What does rostral nasopharyngeal collapse cause?

Answer 3

• INSPIRATORY NOISE
• Causes minor problem
• Something rostral to the pharynx is blocking it

Question 4

What is rostral nasopharyngeal collapse sometimes associated with?

Answer 4

• Occ associated with airway inflammation
  
  • Treat this – Local/systemic anti-inflammatories -throat sprays
  • Lymphoid hyperplasia

Question 5

How does dorsal/lateral nasopharyngeal collapse present, and in what population of horses?

Answer 5

• Much more serious than rostral
• inspiratory noise
• 2-3 YO’s
• Also increasing in older WB dressage horses

Question 6

What are the causes of dorsal/lateral nasopharyngeal collapse?

Answer 6

• 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

Question 7

What are the features of brachycephalic obstructive airway syndrome (BOAS)?

Answer 7

• Pharyngeal collapse (sometimes)
• Stenotic nares
• Excessively long soft palate
• Everted laryngeal saccules

Question 8

What is dorsal displacement of the soft palate (DDSP)?

Answer 8

• 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

Question 9

What are the clinical signs of DDSP?

Answer 9

• Expiratory noise, ‘gurgling’ noise, swallow, open-mouth breathing
• Sometimes have an intermittent cough

Question 10

How is DDSP diagnosed?

Answer 10

• 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

Question 11

Other differentials for DDSP?

Answer 11

• These may be concurrent
• Pulmonary dx
• Cardiac dx
• Lameness
• Neurological dx

Question 12

Non-surgical options for management of DDSP?

Answer 12

• 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)

Question 13

Which type of laryngeal hemiplegia (‘Roarers’/ Recurrent laryngeal neuropathy) is the most common and why?

Answer 13

• 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

Question 14

What can cause right sided laryngeal hemiplegia (‘Roarers’/ Recurrent laryngeal neuropathy)?

Answer 14

• 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

Question 15

What is bilateral laryngeal hemiplegia (‘Roarers’/ Recurrent laryngeal neuropathy) associated with?

Answer 15

• liver disease – unknown aetiology
• Pb toxicity
• OP toxicity
• CNS dx

Question 16

How is laryngeal hemiplegia (‘Roarers’/ Recurrent laryngeal neuropathy) diagnosed?

Answer 16

• History
  
  • Inspiratory noise
• Physical examination
• Endoscopy (resting)
• Treadmill/Overground endoscopy
• Ultrasonography

Question 17

What can cause laryngeal hemiplegia in dogs?

Answer 17

• Large breed dogs
  
  • Hereditary – Husky and husky X
  • Labradors, GR, IS, Newfoundlands, St Bernards
• Concurrently with endocrine disorders incl hypothyroidism
• Head trauma/abscess/neoplasia

Question 18

Clinical signs of epiglottic entrapment?

Answer 18

• Abnormal resp noise at rest and exercise
• May or may not be exercise intolerance

Question 19

Diagnosis of epiglottic entrapment?

Answer 19

• Endoscopy (exercise endoscopy if intermittent, resting if permanent)
• Radiography – assess epiglottic size

Question 20

Clinical signs of subepiglottic cysts?

Answer 20

• Resp noise, (+/-) exercise intolerance, coughing, dysphagia
• Smooth, pink, fluctuant, mucosal covered mass beneath epiglottis
• Not a dynamic disease but can cause DDSP

Question 21

Diagnosis of subepiglottic cysts?

Answer 21

• Endoscopy- nasopharyngeal
• Endoscopy – oral
• Oral examination

Question 22

Causes of dynamic tracheal collapse? (equine)

Answer 22

• Shetlands and miniature horses
• Secondary to peritracheal abscesses/tumours
• Cartilage trauma
• Cartilage malformation
• Often congenital

Question 23

Clinical signs of tracheal collapse? (equine)

Answer 23

• Exercise intolerance, resp distress, stridor (‘goose-honk’)
• Some asymptomatic unless stressed
• Often doesn’t manifest until they start to develop lung disease

Question 24

Diagnosis of tracheal collapse? (equine)

Answer 24

• Auscultation
• Palpation
• Exercise test
• Endoscopy (usually resting)
• Radiography

Question 25

How would you treat tracheal collapse in equids?

Answer 25

• Challenging
• Stent them for a short period
• If much longer very tricky, and more associated with management of LRT disease

Question 26

Causes of tracheal collapse in dogs?

Answer 26

• Toy breeds esp YT
• Genetic, nutritional and inflammatory

Question 27

Treatment of tracheal collapse in dogs?

Answer 27

weight loss, correct underlying inflammatory airway disease and lung disease, may need surgery (stent)