Most approaches to solving "roaring" in horses–a noisy, performance-limiting condition of the equine airway–involve wielding a scalpel, but a Cornell University-based research team recently examined an alternative, treatment for roarers. Jon Cheetham, VetMB, PhD, Dipl. ACVS, of the College of Veterinary Medicine’s Department of Clinical Sciences described this approach at the 2011 American Association of Equine Practitioners convention, held Nov. 18-22 in San Antonio, Texas.

"Recurrent laryngeal neuropathy, also called roaring, is caused by dysfunction of the left recurrent laryngeal nerve resulting in paralysis, either partial or complete, of the left arytenoid cartilage," Cheetham explained. "This paralysis of the arytenoid cartilage, which is part of the larynx, causes poor performance because the airway collapses during exercise, preventing enough air from reaching the lungs. With too little air, the horse’s muscles can’t generate enough energy to contract and function properly."

Roaring is a fairly common problem, affecting an estimated 8% of all Thoroughbreds, as well as many sports horse and draft breeds. As Cheetham previously told TheHorse.com, the current treatment of choice is a "tie-back" surgery to permanently open the abnormal arytenoid cartilage. The overall success rate is moderate (48-68%)..

As an alternative to surgery, Cheetham and colleagues assessed the feasibility of "functional electrical stimulation," or FES, in horses diagnosed as roarers