Epiglottic Entrapment in Epiglottic Entrapment in HorsesHorses

Erica Fields, DVMErica Fields, DVM

Butler, Clinical Radiology of the HorseButler, Clinical Radiology of the Horse

Normal EpiglottisNormal Epiglottis

Curved (dorsally convex), smoothCurved (dorsally convex), smooth

Base nearly vertical Base nearly vertical

Tip at right angle to dorsal surface of Tip at right angle to dorsal surface of the soft palate, pointed, narrowthe soft palate, pointed, narrow

Serrated lateral edgesSerrated lateral edges

Vascular pattern on dorsal surfaceVascular pattern on dorsal surface

Aryepiglottic folds attach to lateral Aryepiglottic folds attach to lateral edgesedges

Butler, Clinical Radiology of the HorseButler, Clinical Radiology of the Horse

Common Epiglottic AbnormalitiesCommon Epiglottic Abnormalities

Epiglottic entrapmentEpiglottic entrapment

Epiglottic shortening (hypoplasia)Epiglottic shortening (hypoplasia)

Subepiglottic cystsSubepiglottic cysts

Ulceration/inflammationUlceration/inflammation

Epiglottic EntrapmentEpiglottic Entrapment

Apex and lateral margins become Apex and lateral margins become enveloped by ventral mucosa and enveloped by ventral mucosa and aryepiglottic foldsaryepiglottic folds

Blunted and shortening of epiglottisBlunted and shortening of epiglottis

Ulceration may occurUlceration may occur

Equine Surgery / www.ctba.comEquine Surgery / www.ctba.com

Clinical SignsClinical Signs

Exercise intolerance at high speedsExercise intolerance at high speeds

Abnormal respiratory sounds at high Abnormal respiratory sounds at high speeds; asymptomatic at restspeeds; asymptomatic at rest

Jockey may report “holding breath”Jockey may report “holding breath”

Mostly problematic in Thoroughbreds Mostly problematic in Thoroughbreds and Standardbredsand Standardbreds

Radiographic AppearanceRadiographic Appearance

Radiographic AppearanceRadiographic Appearance

Radiographic AppearanceRadiographic Appearance

Blunt, short epiglottisBlunt, short epiglottis

May be dorsally or caudally deviatedMay be dorsally or caudally deviated

Must be differentiated from epiglottic Must be differentiated from epiglottic shorteningshortening

Endoscopy is method of choice for Endoscopy is method of choice for diagnosisdiagnosis

Endoscopic AppearanceEndoscopic Appearance

Possible CausesPossible Causes

Definitive cause unknownDefinitive cause unknown

Onset often coincides with training; Onset often coincides with training; inflammation/trauma?inflammation/trauma?

Infection?Infection?

Developmental shorteningDevelopmental shortening

Russell and Wainscott, 2007Russell and Wainscott, 2007

Treatment OptionsTreatment Options

Conservative: topical anti-Conservative: topical anti-inflammatoriesinflammatories

Surgical transection—endoscopic Surgical transection—endoscopic laser transection, Bistoury laser transection, Bistoury transection (blind or endoscopic), transection (blind or endoscopic), resection of a section of fold via resection of a section of fold via ventral laryngotomyventral laryngotomy

Laser TransectionLaser Transection

Laser Transection—Post-opLaser Transection—Post-op

Brown, et al, 2005Brown, et al, 2005

OutcomesOutcomes

Relatively high rate of complication Relatively high rate of complication with surgery (DDSP, re-entrapment)with surgery (DDSP, re-entrapment)

Racehorses affected, so prognosis Racehorses affected, so prognosis involves return to function, not just involves return to function, not just survivalsurvival

Study of horses just off track—0.9% Study of horses just off track—0.9% prevalence, NO ADVERSE EFFECT on prevalence, NO ADVERSE EFFECT on performanceperformance

Hobo, et al, 1995 and Russell and WainscoHobo, et al, 1995 and Russell and Wainscott, 2007tt, 2007

OutcomesOutcomes

Study of clinical horses—0.6% Study of clinical horses—0.6% prevalence prevalence

Post-op study—26/27 horses raced Post-op study—26/27 horses raced again; 13/27 improved in handicap, again; 13/27 improved in handicap, 13/27 decreased handicap13/27 decreased handicap

ReferencesReferencesBrown JA, Hinchcliff KW, Jackson MA, Dredge AF, Brown JA, Hinchcliff KW, Jackson MA, Dredge AF, O’Callaghan PA, McCaffrey JP, Slocombe RF, Clarke AF. O’Callaghan PA, McCaffrey JP, Slocombe RF, Clarke AF. Prevalence of pharyngeal and laryngeal abnormalities in Prevalence of pharyngeal and laryngeal abnormalities in Thoroughbreds racing in Australia, and their association Thoroughbreds racing in Australia, and their association with performance. Equine Veterinary Journal. (2005) 37(5): with performance. Equine Veterinary Journal. (2005) 37(5): 397-401397-401Butler, Clinical Radiology of the HorseButler, Clinical Radiology of the HorseEquine Surgery textbookEquine Surgery textbookHobo S, Matsuda Y, Yoshida K. Prevalence of upper Hobo S, Matsuda Y, Yoshida K. Prevalence of upper respiratory tract disorders detected with a flexible respiratory tract disorders detected with a flexible videoendoscope in Thoroughbred racehorses. Journal of videoendoscope in Thoroughbred racehorses. Journal of Veterinary Medical Science. (1995) 57(3): 409-413.Veterinary Medical Science. (1995) 57(3): 409-413.Russell T, Wainscott M. Treatment in the field of 27 horses Russell T, Wainscott M. Treatment in the field of 27 horses with epiglottic entrapment. The Veterinary Record. (2007) with epiglottic entrapment. The Veterinary Record. (2007) 161: 187-189.161: 187-189.