Page 522 - The Veterinary Care of the Horse

procedure called PENS (percutaneous electrical nerve stimulation) can reduce or abolish the

headshaking in some horses and ponies. It does not work for every horse.
VetBooks.ir front of the horse’s face and a second needle into the brachiocephalic muscle at the base of
An acupuncture needle or PENS probe is placed close to the infraorbital nerve on the

the horse’s neck. A small electrical current is then run between the needles with an

alternating high and low frequency and the intensity is slowly increased until the nostrils
show a gentle muscle twitch for a period of around 25 minutes. This is not uncomfortable for
the horse and the procedure, which is carried out under light sedation, is well tolerated. Both

procedures work by activating nerve pathways that inhibit the transmission of the unpleasant
pain signals the horses are experiencing.

The response is variable but a significant number of horses experience remission periods
of many weeks or months after three to five treatments. Long-term remission has been seen

in some horses treated with electroacupuncture (Figure 11.14).