ESOPHAGEAL DYSFUNCTION IN DOGS WITH IDIOPATHIC LARYNGEAL PARALYSIS: A CONTROLLED COHORT STUDY

Abstract

Objectives: To compare esophageal function in dogs with idiopathic laryngeal paralysis (ILP) to age- and breed-matched controls; to determine if dysfunction is associated with aspiration pneumonia over one year; and to compare clinical neurologic examination of dogs with ILP at enrollment and one year. Study Design: Prospective controlled cohort study Animals or Sample Population: 32 dogs with ILP, and 34 age- and breed-matched healthy dogs. Methods: Three-phase esophagrams were performed on all dogs. Blinded analyses of the esophagrams were performed, and the mean esophageal score determined in each phase. Following unilateral crico-arytenoid laryngoplasty, dogs with ILP were re-examined including thoracic radiography at 1, 3, 6 and 12 months. Neurologic status was recorded at enrollment, 6 and 12 months. Results: Esophagram scores in dogs with ILP were significantly higher in each phase compared to the controls, most notably with liquid (P<.0001). Dysfunction was more pronounced in the cervical and cranial thoracic esophagus. The 5 dogs that experienced aspiration pneumonia during the study period had significantly higher esophagram scores than the dogs that did not develop aspiration pneumonia (P<0.02). Ten of the 32 (31%) dogs with ILP had generalized neurologic signs upon enrollment and all (100%) dogs developed neurologic signs over one year (P<.0001). Conclusions: Dogs with ILP also have esophageal dysfunction. Post-operative aspiration pneumonia is more likely in dogs with higher esophagram scores. Dogs with ILP will most likely develop generalized neuropathy over the course of a year. Clinical Relevance: Esophagrams and neurologic examinations should be performed on all dogs with ILP.