Laryngeal Paralysis: Pathophysiology, Diagnosis, and Surgical Repair

CE Dysfunction of the recurrent laryngeal nerves causes laryngeal paralysis in dogs and cats. Paralysis of the cricoarytenoideus dorsalis muscle results in an inability to abduct the arytenoid cartilages during inspiration.The resulting cross-sectional area of the glottis is inadequate for normal respiration.The most common clinical signs of laryngeal paralysis in dogs and cats are stridor, exercise intolerance, respiratory distress, and a change in phonation. A variety of surgical procedures have been used to successfully treat laryngeal paralysis in dogs and cats. Arytenoid lateralization appears to give the best clinical outcome. dogs are more commonly affected than female dogs. Reported canine male:female ratios range from 3.7:1 to 1:1. The mean age range of dogs treated surgically for laryngeal paralysis is 9.5 to 12.2 years of age. Labrador retrievers are most commonly affected with acquired laryngeal paralysis. Other commonly affected large and giant breeds include the St. Bernard, Irish setter, and Afghan hound. One report described the prevalence of laryngeal paresis and paralysis in a population of dogs undergoing general anesthesia at a university veterinary teaching hospital. The investigators performed laryngoscopy on 250 dogs, assigning each dog a subjective score of 0 (i.e., normal) to 4 (i.e., completely paralyzed). One-quarter of the dogs examined had some degree of laryngeal paresis. Laryngeal scores were significantly and directly related to age, body weight, and body condition score. Labrador retrievers and rottweilers were at least twice as likely to be affected as other breeds. No effort was made to standardize the anesthetic protocol. This could be important because the most commonly used anesthetic drugs depress laryngeal motion. November 2005 857 COMPENDIUM Laryngeal Paralysis: Pathophysiology, Diagnosis, and Surgical Repair John F. Griffin IV, DVM D. J. Krahwinkel, DVM, MS, DACVS, DACVA, DACVECC University of Tennessee Send comments/questions via email [email protected] or fax 800-556-3288. Visit CompendiumVet.com for full-text articles, CE testing, and CE