Laryngeal paralysis is a common disorder of older, large-breed dogs. Denervation of the cricoarytenoideus dorsalis muscle of the larynx causes the vocal folds and arytenoid cartilages to fail to abduct during inspiration, creating an upper airway obstruction. Although the etiology is usually unknown, trauma and neoplasia can cause laryngeal paralysis. Which of the following conditions can also cause laryngeal paralysis?