Acute Life-threatening Laryngeal Dysfunction in a Draft Horse Recovering from General Anesthesia: A Case Report.

A 13-year-old Shire horse was anesthetized for an elective orthopedic procedure. During recovery from anesthesia, the occurrence of severe acute dyspnea required a second anesthetic to allow endoscopy-guided nasotracheal intubation. Endoscopic findings were decreased mobility and swelling of the arytenoids with narrowing of the laryngeal aditus. Owing to a dislodgement of the nasotracheal tube during recovery, a third anesthetic was carried out to perform emergency tracheostomy. Recovery from the third anesthetic was long and the horse developed a post-anesthetic myopathy. The clinical conditions improved during the following 48 hours, and an endoscopic examination performed before discharge revealed unremarkable laryngeal function. It was hypothesized that mechanical stimulation of the trachea during the phases of intubation and extubation caused traumatic laryngeal dysfunction, and that draft horses might require additional care during the perioperative period.