Guttural Pouch Tympany
Introduction
- Congenital defect of ostia (drainage openings of guttural pouches into pharynx)
- Potentially secondary to inflammation
- Unilateral or bilateral
- Marked retropharyngeal swelling
- Abnormal distention of pouch with air
- Congenital defect of plica salpingopharyngium - one way valve trapping air
- Occurs more in fillies than colts
3. Guttural Pouch Tympany:
- Foals up to one year of age. The guttural pouch fills with air, but cannot escape through the pharyngotubal opening (acts as a one-way valve allowing air to be drawn into the pouch, but not expelled from it). Usually there is no gross abnormality of the opening.
- Visible external swelling and large pouch on radiographs.
- Consequences: collapse of pharyngeal roof, and therefore dysphagia.
- Unilateral tympany can be treated by forcing an opening in the median septum (fenestration) so that both pouches communicate with the pharynx through a single opening.
- Bilateral tympany - parts of the flaps guarding the openings may have to be removed.