Endoscopy is the current diagnostic method of choice for evaluating the equine upper airway. However, veterinarians at Cornell University for the first time have described ultrasound techniques for evaluating the equine larynx, and they say the diagnostic procedure could become useful as an additional way to evaluate the equine upper airway.

“Nasopharyngeal and laryngeal evaluation is important when examining horses with upper airway signs for poor performance,” said the authors in their study, which appeared in the September-October issue of Veterinary Radiology & Ultrasound. They examined the larynges of six equine cadavers and four standing horses to establish its appearance on ultrasound.
 
“A scanning technique, including useful acoustic windows and the normal ultrasonographic appearance at each site, is described,” the authors wrote. “Ultrasound allowed visualization of portions of the hyoid apparatus, laryngeal cartilages, associated soft tissues, and intrinsic and extrinsic laryngeal musculature, that are not seen using endoscopy.

Also, using real-time ultrasound, the veterinarians were able to watch the movement of vocal folds and arytenoid cartilages during respiration, and ultrasonography helped them diagnose and localize arytenoid abcessation and perilaryngeal inflammation in three horses with arytenoid chondritis (inflammation of the arytenoid cartilage).

“The establishment of this technique will serve as the basis for future investigations in the evaluation of clinical patients with upper airway abnormalities,” the authors concluded