Transient Horner's syndrome in horses following cervical plexus local anesthesia

Abstract

Objective: To report the development of transient Horner's syndrome in horses following local anesthesia of the cervical plexus.

Animals: A total of 37 horses.

Study design: Observational retrospective short case series.

Methods: Medical records of cases undergoing ultrasound-guided cervical plexus anesthesia for standing prosthetic laryngoplasty at a single referral institution were evaluated (2019-2020).

Results: Five of 37 horses (14%) developed transient signs of Horner's syndrome postoperatively. Obvious clinical signs began 2 to 5 h following local anesthesia and persisted for two to 4 h. Profuse unilateral sweating of the head and upper neck was the most apparent clinical sign.

Conclusion: Transient clinical signs of Horner's syndrome were seen following unilateral local anesthesia of the cervical plexus. Long-term adverse sequelae were not observed.