Severe auricular skin necrosis as potential postanaesthetic complication in a horse undergoing general anaesthesia for orthopaedic surgeries.

The study reports on a case where a horse developed severe skin necrosis in the auricular region following multiple anesthetics for orthopedic surgeries, with implications that incorrect head positioning during anesthesia contributing to the problem.

Study Subject

• The subject of the study was a 5-year and 8-month-old Trotter mare that had previously undergone screw fixation of a third carpal bone fracture.
• The horse presented severe thoracic limb lameness two years after the initial surgery, which was diagnosed as septic arthritis of the intermediate carpal joint.

Diagnostic and Treatment Procedures

• To address the issue, the horse underwent three additional anesthetics over the course of treatment.
• The first two anesthetics were administred for performing arthroscopic lavages in dorsal recumbency.
• The third anesthetic was for a computed tomography-guided screw explantation with curettage of the infected, sclerotic third carpal bone in right lateral recumbency.
• The anesthetic used for each operation was isoflurane carried in oxygen and air, combined with a constant rate infusion of medetomidine.

Post-Anaesthetic Complication

• Twelve days after the third anaesthetic, the horse suffered from severe skin necrosis of the right pinna.
• Despite this, the affected region fully healed over the course of six weeks.
• The authors suggest the complication might have been due to incorrect head positioning during anaesthesia, which would have led to ischemic tissue damage. However, a definitive cause could not be positively established.

Goal of the Report

• This report primarily serves to raise awareness on potential anesthetic complications in horse orthopedic surgeries.
• Specifically, it underlines the need to carefully manage horse head positioning during anaesthesia, given the potential for ischemic tissue damage leading to skin necrosis.