Guttural Pouch Diseases Flashcards
What are the guttural pouches?
diverticula of the eustachian tubes, which communicate with the pharynx and can be endoscopically visualized
- unique to the horse
- undefined function
What divides the guttural pouch into medial and lateral segments?
stylohyoid bone
What neural structures are found in the guttural pouch?
- CN VII, IX, X, XI, and XII
- sympathetic truk
What vascular structures are found in the guttural pouch?
- internal and external carotids
- maxillary arteries
Guttural pouch contents:
What is guttural pouch tympany? What is a potential cause?
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
What clinical signs are associated with guttural pouch tympany?
- non-painful swelling in the throat-latch region of a foal
- respiratory stertor
- respiratory difficulty
- dysphagia
- aspiration pneumonia
How is guttural pouch tympany diagnosed?
- signalment - foal!
- clinical signs
- radiographic evidence of an air-filled guttural pouch
What treatment is recommended for foals with guttural pouch tympany?
surgical correction
- unilateral - fenestration of median septum that separates the 2 guttural pouches
- bilateral - resection or modification of pharyngeal orifice
What is prognosis of guttural pouch tympany like?
- uncomplicated = good
- dysphagia, aspiration pneumonia = fair to guarded
What is guttural pouch empyema?
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
What clinical signs are indicative of guttural pouch empyema?
- 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
How is guttural pouch empyema diagnosed?
- history of upper respiratory tract infection
- PE + clinical signs
- confirmed with endoscopy or radiography
Guttural pouch empyema, radiograph:
fluid line
How is guttural pouch empyema treated?
- 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
What is guttural pouch mycosis? What is the pathogenesis?
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
What clinical signs are associated with guttural pouch mycosis?
- hemorrhage, epistaxis episodes –> commonly fatal!
- dysphagia, Horner’s syndrome, or facial nerve paralysis due to involvement of cranial nerves
How is guttural pouch mycosis diagnosed?
- clinical signs
- endoscopy - blood clots and fungal plaques seen in guttural pouch
What treatments are recommended in cases of guttural pouch mycosis?
- surgical occlusion of affected arteries
- administer anti-fungal medications (less efficacious)
What is prognosis like in cases of guttural pouch mycosis?
guarded to fair - dysphagia can worsen the prognosis as it may take a prolonged time for neural structures to recover
