Help for RoarersBy Kentucky Equine Research Staff · April 1, 2011
Roaring, equine recurrent laryngeal neuropathy, laryngeal paralysis…no matter what you call it, that loud whistling noise when a performance horse breathes is bad news. The most current term, recurrent laryngeal neuropathy (RLN), refers to paralysis of one side (the left side is most often affected) of the horse's larynx. When the larynx can't open fully to allow air to pass through, the restriction causes noisy breathing, a drop in exercise tolerance, and declining performance. RLN profoundly affects about 3 to 5% of Thoroughbred racehorses, though many more have at least mild problems with larynx function. Australia's Rural Industries Research and Development Corporation is conducting studies to determine the regenerative potential of the left cricoarytenoideus dorsalis muscle and the nerves that control its action on the larynx. The research will also look for a way to identify subclinically affected horses and those that may develop the problem in the future.