Comparison of bacterial cultures of the larynx between dogs with laryngeal paralysis and normal dogs

OBJECTIVE : To document the most common types of bacteria isolated from the canine larynx and to compare isolates, degree of growth and susceptibility patterns between dogs with laryngeal paralysis and dogs with normal laryngeal function. METHODS : Laryngeal swabs were collected from each patient and submitted for bacterial culture and susceptibility testing. Dogs with laryngeal paralysis (n = 23) underwent a unilateral arytenoid lateralisation and control dogs (n = 24) underwent an elective orthopaedic procedure. Results of the cultures were compared between groups. RESULTS : Bacterial organisms isolated from the larynx were similar to those normally found in the oropharynx, trachea and lungs. The most common bacteria isolated from the larynges of all dogs were Escherichia coli, Klebsiella species and Pasteurella species. Pure colonies were more commonly seen in dogs with laryngeal paralysis while mixed colonies were more commonly seen in control dogs. Antimicrobial resistance was similar between study and control dogs. CLINICAL SIGNIFICANCE : The laryngeal flora appears to contain bacteria that are commonly isolated from the oropharynx, trachea and lungs. Differences in antimicrobial susceptibility were not identified between study and control dogs.