87 (5) pg 283

Laryngeal hemiplegia in the horse: an update

Laryngeal hemiplegia is a progressive upper airway dysfunction in the horse. It is not onlyseen in thoroughbred racehorses but also in warmblood horses, draft horses and in ponies. Thecondition is most frequently seen on the left side. The left laryngeal recurrent nerve graduallyloses function and the function of the left cricoarythenoideus dorsalis muscle is compromised.This condition is most often idiopathic. It possibly leads to exercise intolerance but a respiratorynoise is often the primary complaint of the owner. Right sided laryngeal hemiplegia is almostalways related to other pathologies causing the nerve to malfunction. The diagnosis is not alwayseasy because of the restricted availability of endoscopy in the field. A better understanding oflaryngeal ultrasound examination might offer a new possibility in diagnosing laryngeal hemiplegia.If abnormal inspiratory sound is the only problem, laser treatment alone can be satisfactory.If the horse shows clear signs of exercise intolerance, further treatment is needed. If correctlyexecuted, the outcome of laryngoplasty is good. Other techniques, like nerve grafting and pacemakers,are being explored and might even be regarded as better alternative treatments in thefuture, as these are more physiologic compared to laryngoplasty. In sporthorses presented withidiopathic laryngeal neuropathy without postoperative complications, the prognosis is good.

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