Persistent dorsal displacement of the soft palate attributable to a frenulum of the epiglottis in a racing Thoroughbred.

The research investigates the case of a 7-year-old male racehorse with exercise intolerance, respiratory noise, and coughing while eating, caused by an unusual occurrence of the soft palate moving towards the back due to a tissue band connecting the epiglottis and the underside of the tongue. This condition was treated by cutting the tissue band using a diode laser. However, the issue repeated four weeks post-surgery.

Case Evaluation

• The horse in question was a 7-year-old male Thoroughbred racehorse, presenting symptoms such as difficulties during exercise, making respiratory noises, and coughing while eating.
• An endoscopic examination was conducted to evaluate the upper regions of the respiratory tract.
• This examination revealed a persistent dorsal (or rearward) displacement of the soft palate – unusual in horses.

Findings

• Further investigation through radiography exposed a hypoplastic epiglottis (underdeveloped) that was positioned ventral to the soft palate and had no contact with it. Normally, the epiglottis rests on top of the soft palate.
• During an oral endoscopic examination conducted under anaesthesia, a subepiglottic frenulum was detected. This is an abnormal tissue band running from the epiglottis to the underside of the tongue.
• The researchers postulate that it was this frenulum that caused the dorsal displacement of the soft palate.

Treatment and Post-Care

• The frenulum was severed transendoscopically using a diode laser.
• Post-op examinations (endoscopic and radiographic) 24 hours after surgery showed that the epiglottis had returned to its normal anatomical position in relation to the soft palate.
• However, four weeks after the operation, an endoscopic examination revealed recurrence of the dorsal displacement of the soft palate.

Conclusions

• The researchers suggest that a subepiglottic frenulum should be considered as one of the possible causes for persistent dorsal displacement of the soft palate in horses.
• An endoscopic examination of the oropharyngeal region (mouth and pharynx) in horses is recommended before carrying out any surgical interventions to address the persistent dorsal displacement of the soft palate.