
08/29/2025
Electroacupuncture (EA) has been used successfully as a treatment for trigeminal nerve-mediated head-shaking (TMHS) in horses.
Head-shaking in horses can be a clinical sign of a wide variety of conditions from a poorly fitting bridle/bit to dental or sinus disease and a range of other issues. TMHS is the most common diagnosis, usually made by process of elimination for other possible issues.
TMHS is a painful and distressing condition where horses exhibit uncontrollable head shaking and flicking. This can make it dangerous for them to be ridden and, in the most severe cases, may lead to euthanasia. Although the exact cause remains unknown, the condition is believed to be triggered by excessive reactions in the trigeminal nerve to external stimuli.
No treatment has been identified that works universally and improvement with any given treatment is seen in 20-50% of affected horses.
The most recent progress in treatment of TMHS has been the use of neuromodulatory therapy, either by percutaneous electrical nerve stimulation (EquiPENSTM) or by electroacupuncture (EA). Both treatments apply electrical stimulation to the infraorbital nerve, which aims to adjust the perception of incoming painful stimuli by inhibiting afferant pain signals and activating descending inhibitory pathways.
A study, which looked at 42 horses treated between 2015 and 2024, revealed positive outcomes. Impressively, 64% of the horses demonstrated some improvement, and a third experienced a complete resolution of the symptoms. However, a small percentage –31% – did not see any improvement, and two horses (about 5%) had their symptoms worsen following treatment.
Electroacupuncture was well tolerated by all the horses, with minimal complications. Its success rate is comparable to similar treatments, like percutaneous electrical nerve stimulation (PENS), and it offers the advantage of being performed in a yard setting, without the need for a veterinary hospital visit.
While not a cure-all, electroacupuncture could provide much-needed relief for both horses and their owners, offering a non-invasive treatment option with fewer risks than many other interventions.