Guttural Pouch Diseases

Question 1

What are the guttural pouches?

Answer 1

diverticula of the eustachian tubes, which communicate with the pharynx and can be endoscopically visualized

• unique to the horse
• undefined function

Question 2

What divides the guttural pouch into medial and lateral segments?

Answer 2

stylohyoid bone

Question 3

What neural structures are found in the guttural pouch?

Answer 3

• CN VII, IX, X, XI, and XII
• sympathetic truk

Question 4

What vascular structures are found in the guttural pouch?

Answer 4

• internal and external carotids
• maxillary arteries

Question 5

Guttural pouch contents:

Answer 5

Question 6

What is guttural pouch tympany? What is a potential cause?

Answer 6

non-painful distension of the guttural pouch with air, resulting in a noticeable external swelling of the throat-latch region of the foal –> congenital!

abnormal or excessive mucosal flap at the pharyngeal orifice acting as a one-way valve allowing air to get trapped in the guttural pouch

Question 7

What clinical signs are associated with guttural pouch tympany?

Answer 7

• non-painful swelling in the throat-latch region of a foal
• respiratory stertor
• respiratory difficulty
• dysphagia
• aspiration pneumonia

Question 8

How is guttural pouch tympany diagnosed?

Answer 8

• signalment - foal!
• clinical signs
• radiographic evidence of an air-filled guttural pouch

Question 9

What treatment is recommended for foals with guttural pouch tympany?

Answer 9

surgical correction

• unilateral - fenestration of median septum that separates the 2 guttural pouches
• bilateral - resection or modification of pharyngeal orifice

Question 10

What is prognosis of guttural pouch tympany like?

Answer 10

• uncomplicated = good
• dysphagia, aspiration pneumonia = fair to guarded

Question 11

What is guttural pouch empyema?

Answer 11

accumulation of purulent exudate in the guttural pouch secondary to an upper respiratory infection of Streptococcus equi or zooepidemicus or rupture of retropharyngeal LN into the pouch

Question 12

What clinical signs are indicative of guttural pouch empyema?

Answer 12

• nasal discharge - may continue after apparent resolution of respiratory infection
• regional LN enlargement
• dysphagia
• chronic infection = inspissation of exudate result in firm masses called chondroids

Question 13

How is guttural pouch empyema diagnosed?

Answer 13

• history of upper respiratory tract infection
• PE + clinical signs
• confirmed with endoscopy or radiography

Question 14

Guttural pouch empyema, radiograph:

Answer 14

fluid line

Question 15

How is guttural pouch empyema treated?

Answer 15

• aggressive guttural pouch lavage
• local and systemic antimicrobials
• surgical lavage and drainage, especially if chondroids are present

maintain isolation protocols if S. equi is suspected

Question 16

What is guttural pouch mycosis? What is the pathogenesis?

Answer 16

fungal plaque development in the guttural pouch, most commonly on the dorsal aspect

development of Aspergillus plaques causes erosion of the walls of one of the arteries, resulting in epistaxis or dysphagia due to involvement of cranial nerves

Question 17

What clinical signs are associated with guttural pouch mycosis?

Answer 17

• hemorrhage, epistaxis episodes –> commonly fatal!
• dysphagia, Horner’s syndrome, or facial nerve paralysis due to involvement of cranial nerves

Question 18

How is guttural pouch mycosis diagnosed?

Answer 18

• clinical signs
• endoscopy - blood clots and fungal plaques seen in guttural pouch

Question 19

What treatments are recommended in cases of guttural pouch mycosis?

Answer 19

• surgical occlusion of affected arteries
• administer anti-fungal medications (less efficacious)

Question 20

What is prognosis like in cases of guttural pouch mycosis?

Answer 20

guarded to fair - dysphagia can worsen the prognosis as it may take a prolonged time for neural structures to recover