Congenital laryngeal paralysis causing breathing trouble in Alaskan

Abstract

OBJECTIVE To characterize congenital laryngeal paralysis (CLP) in Alaskan Huskies. DESIGN Prospective case series. ANIMALS 25 Alaskan Huskies with CLP. PROCEDURES Data were collected for each dog regarding signalment; history; results of physical, orthopedic, neurologic, and laryngeal examinations; esophagraphic findings; treatments; histologic findings; and outcomes. RESULTS Severely affected dogs were profoundly dyspneic at birth or collapsed after brief exercise; less affected dogs reportedly tired easily or overheated with minimal exercise. Mean age at initial onset of clinical signs was 6.4 months. Blue eyes, white facial markings, and oral mucosal tags or tissue bands were noted in 23 (92%), 19 (76%), and 13 (52%) dogs. Neurologic examination revealed signs of mononeuropathy of the recurrent laryngeal nerve but not of polyneuropathy. Histologic examination revealed neurogenic atrophy of the cricoarytenoideus dorsalis muscle but no polyneuropathy. Eight (32%) dogs underwent unilateral cricoarytenoid lateralization, resulting in substantial clinical improvement, including ability to compete in sled dog races. Without surgery, 4 (16%) dogs died of asphyxiation, 10 (40%) had spontaneous improvement of clinical signs (but insufficient improvement to race), and 3 (12%) remained affected. Results of pedigree analysis suggested an autosomal recessive mode of CLP inheritance, with variable penetrance. CONCLUSIONS AND CLINICAL RELEVANCE CLP in the evaluated Alaskan Huskies involved mononeuropathy of the recurrent laryngeal nerves, without polyneuropathy. Most affected dogs had blue eyes, white facial markings, and oral mucosal tags or tissue bands. Given the apparent genetic component to CLP in this breed, we recommend that dogs with these features be prevented from breeding.