Use of successive dynamic videoendoscopic evaluations to identify progression of recurrent laryngeal neuropathy in three horses.

The research article discusses how videoendoscopic evaluations were used to identify the progression of recurrent laryngeal neuropathy—a condition that impairs function of the larynx or voice box—in three racehorses.

Methodology and Results

• The three racehorses were selected for evaluation due to their poor performance or abnormal noise originating from the upper portion of their respiratory tract.
• During maximal exercise, an initial dynamic videoendoscopy of the upper respiratory tract revealed complete arytenoid cartilage abduction—an open position of the voice box cartilage— in two horses, and incomplete but adequate abduction of the same cartilage in the third horse.
• Upon subsequent exercising endoscopic evaluation, all three horses were found to have severe dynamic collapse of the left arytenoid cartilage and vocal fold. This condition included the inability of the voice box cartilage to open completely, restricting the airflow and leading to the unusual noises and poor performance.

Treatment and Conclusion

• Two of the horses were treated with prosthetic left laryngoplasty, a surgical procedure that helps in enhancing the airflow by allowing for wider abduction of the arytenoid cartilage. After the surgery, these two horses were able to race successfully.
• The third horse was retired from racing due to its condition.
• Through this research, the authors concluded that idiopathic laryngeal hemiplegia, a condition causing partial or complete paralysis of the arytenoid cartilage, can be a progressive disease.
• The study demonstrated the importance of successive dynamic videoendoscopic upper airway evaluations in confirming the progression of left laryngeal hemiplegia in horses. Therefore, videoendoscopy of the upper respiratory tract during exercise should be considered as part of the clinical evaluation of horses with signs of upper respiratory tract dysfunction.