Exercising videoendoscopic evaluation of 45 horses with respiratory noise and/or poor performance after laryngoplasty.

This study aimed to evaluate the upper respiratory function of horses that were performing poorly post-laryngoplasty using videoendoscopy. The researchers wanted to establish if any dynamic collapse of the left arytenoid could be predicted by the amount of postsurgical abduction at rest.

Methodology

• The study is a case series involving 45 horses, all of which had undergone left laryngoplasty in the time period between June 1993 and December 2007.
• Only horses that had video records of both resting and exercising upper airway endoscopy were included in this research.
• The degree of resting postsurgical abduction was categorized for each horse after the surgery.
• Researchers also evaluated and categorized the amount of postsurgical abduction immediately after the surgery for those horses with endoscopy recordings.
• The team then looked at the relationship between the degree of restful post-surgery abduction and the horses’ historical information with their findings under endoscopic assessment during exercise.

Results

• The findings showed a dynamic collapse of the left arytenoid cartilage in horses with no postsurgical abduction. However, for horses with grade 3 and 4 postsurgical abductions, this collapse couldn’t be predicted.
• Respiratory noise was discovered in relation to the upper airway obstruction, but not specifically associated with the arytenoid collapse.
• It was also noted that most horses with a left vocal fold experienced the billowing of the fold during exercise.
• The team found out that other forms of dynamic collapse involved the right vocal fold, aryepiglottic folds, the corniculate process of the left arytenoid cartilage, dorsal displacement of the soft palate, and pharyngeal collapse.
• Complex obstructions were present in most examinations and in every horse with exercise-induced collapse of the left arytenoid cartilage.

Conclusion

• The conclusion from this study stated that there was no direct relationship found between the exercising collapse of the left arytenoid cartilage and grade 3 or 4 postsurgical abduction.
• However, such a collapse was likely to occur in horses with no postsurgical abduction.