Disease of Equine head + neck 3

Question 1

What separates the nasopharynx + oropharynx?

Answer 1

*Soft palate

Question 2

The pharynx lacks rigid support by bone, What does this mean it’s prone to?

Answer 2

*Collapse

Question 3

What is the function of the pharynx?

Answer 3

*Passage of air
*Passage of ingesta

Question 4

What innervates the pharynx?

Answer 4

*CN 5, 10 + 11
*Cervical nerves

Question 5

What is the function of the larynx?

Answer 5

*Breathing
*Protect lower airway
*Vocalisation

Question 6

What are the 4 parts of the larynx?

Answer 6

*Cricoid cartilage
*Thyroid cartilage
*Epiglottis
*Paired arytenoid cartilages

Question 7

What are the 3 processes of the arytenoid cartilages?

Answer 7

*Muscular process - cAD muscles attachment (cricoarytenoideus dorsalis)
*Corniculate process - in the airway
*Vocal process - vocal cord attachment

Question 8

What causes opening of the glottis? (abduction)

Answer 8

*Cricoarytenoideus dorsalis muscle
-innervation = recurrent laryngeal nerve

Question 9

What causes closure of the glottis? (Adduction)

Answer 9

*Cricoarytenoideus lateralis muscle
-innervation = recurrent laryngeal nerve

Question 10

What are key presenting signs of disease of the larynx + pharynx?

Answer 10

*Respiratory noise - inspiratory
*Exercise intolerance
*Poor performance

Question 11

What can be used to diagnose larynx + pharynx problems?

Answer 11

*Endoscopy
-at rest = look at structures
-at exercise = dynamic problems
*Ultrasound
*Radiography
*CT
*MRI

Question 12

What are clinical signs of pharynx problems?

Answer 12

*Poor performance
*Resp noise
*Dysphagia
*Resp distress
*Nasal discharge
*Coughing

Question 13

What are key disorders of the pharynx?

Answer 13

Dorsal displacement of the soft palate (DDSP)
-intermittent / persistent
*Naso-pharyngeal collapse
*Pharyngeal lymphoid hyperplasia
*Cleft palate
*Foreign body
*Pharyngeal mass

Question 14

What is intermittent DDSP?

Answer 14

*Dynamic condition - only during intense exercise (dynamic endoscopy for Dx)
*Soft palate displaces = expiratory obstruction, horse slows down

Question 15

What is persistent DDSP?

Answer 15

*Soft palate permanently displaced over epiglottis - can’t replace on swallowing
-may have nasal discharge with food material

Question 16

What are pathogenesis of intermittent DDSP?

Answer 16

Neuromuscular dysfunction - pharyngeal branch of Vagus (CN x)
*Lower airway disease
*Structural abnormalities

Question 17

How is DDSP diagnosed?

Answer 17

Endoscopy - exercising

Question 18

What is intermittent DDSP conervative treatment?

Answer 18

*Maturity - happens more in youngsters
*get horse fit - train resp muscles
*Change tack - keep mouth closed
*Tongue tie

Question 19

What are surgical treatment of intermittent DDSP?

Answer 19

*Tie larynx forward - best efficacy
*Palatoplasty - burn so that scarring + thicker soft palate + more stable

Question 20

What happens with nasopharyngeal collapse in neonates?

Answer 20

*Dysphagia
*Self resolves

Question 21

What can cause dynamic pharyngeal collapse?

Answer 21

*Neck flexion - dressage / show ponies

Question 22

What is seen wtih cleft palate?

Answer 22

*Congenital - can cause inhalational pneumonia
*Milk seen coming from nostrils

Question 23

What is diagnosis + treatment of cleft palate?

Answer 23

*Dx = oral exam - endoscopy

*Surgical repair - but not often attempted as difficult + expensive
*Get off milk so inhalation less likely + feed solid material

Question 24

What are laryngeal disorders?

Answer 24

Recurrent laryngeal neuropathy (RLN)
* Fourth branchial arch defect (4-BAD)
* Dynamic laryngeal disorders
* Arytenoid chondritis
* Epiglottic abnormalities

Question 25

What are key clinical signs of laryngeal disorders?

Answer 25

* Respiratory noise * Poor performance * Dysphagia * Coughing * Respiratory distress

Question 26

What side is RLN (recurrent laryngeal neuropathy) more common?

Answer 26

Left - longer as it goes to aortic arch = more prone to injury

Question 27

How is a RLN diagnosed?

Answer 27

*Large breeds *History - poor performance *Endoscopy - asymmetry of arytenoid cartilage

Question 28

What are the different grades of laryngeal function

Answer 28

*Grade 1 = normal *Grade 2 = can fully abduct but doesn't stay there *Grade 3 = can't fully abduct *Grade 4 = complete paralysis

Question 29

How do you treat RLN?

Answer 29

*Tie back -out of the way (prosthetic laryngoplasty) *Arytenoidectomy *Laryngeal re-innervation - nerve graft

Question 30

What are complications of prosthetic laryngoplasty? (tie back)

Answer 30

*Coughing *Seroma *Infection *Dysphagia *Prosthetic failure *Chondritis

Question 31

What are DDx for laryngeal paralysis?

Answer 31

*Unilateral =guttural pouch mycosis, previous surgery, perivascular injection *Bilateral = Hepatic disease, toxicity, post anaesthetic complication

Question 32

What is laryngeal dysplasia?

Answer 32

*Congenital - 4/6th branchial arch deformity *LAryngeal dysfunction - limited abduction of right arytenoid

Question 33

What can be done about vocal cord collapse?

Answer 33

*V loud noise *Tx = vocalcordectomy

Question 34

What is epiglottic entrapment? Tx?

Answer 34

*Epiglottic cartilage trapped by subepiglottic tissue *CS = resp noise, coughing *Dx = endoscopy *Tx = laser resection

Question 35

What is sub epiglottic cyst? What can be done?

Answer 35

*Congenital *Dx = endoscopy *Tx = laser excision / snare excision

Question 36

What is arytenoid chondritis? What can be done?

Answer 36

*Infection of arytenoid cartilage = resp noise, obstruction *Dx = endoscopy *Tx = antibiotics, arytenoidectomy