Epiglottic retroversion as a cause of upper airway obstruction in two horses.

The research paper investigates a newly observed cause of upper airway obstruction in horses termed as “epiglottic retroversion,” which was identified through high-speed treadmill examination.

Background

• Horses, like other animals and humans, can suffer from various upper respiratory tract disorders. These disorders often result in severe respiratory compromise and poor performance, especially in sports or racing horses.
• Traditional diagnostic approaches have involved resting endoscopic examination. While this method can detect visible structural abnormalities, it may not accurately depict dysfunctions occurring during physical exertiveness or high-activity states.

Study Context

• This study covers two specific cases of horses brought to the George D. Widener Hospital. Interestingly, in these cases, no significant abnormalities appeared in the initial resting endoscopic examination.
• The team then subjected the horses to a high-speed treadmill examination. This type of examination mimics physical exertion and allows for dynamic assessment of the horse’s respiratory tract during active states.

Key Findings

• Upon high-speed treadmill examination, a previously unreported disorder, termed as “epiglottic retroversion,” was identified in both horses. Epiglottic retroversion refers to an abnormal backward folding or twisting of the epiglottis, a leaf-shaped flap in the throat that prevents food and liquid from entering the airway. The disruption of this structure’s normal functioning can lead to upper airway obstruction – a severe and potentially life-threatening condition in horses.

Conclusion and Implications

• This study’s findings highlight the limitation of resting endoscopic examinations in detecting all types of upper respiratory tract dysfunction in horses. More importantly, they underline the importance of exercise-stimulated examinations, like high-speed treadmill examination, in identifying dynamic disorders such as epiglottic retroversion.
• The discovery of this new disorder also expands the understanding of respiratory diseases in equine animals and provides a new direction for further research and potential treatment protocols.