Wound Healing in Horses: Research on Light Therapy

When nursing skin wounds of horses, such as lacerations or deep abrasions, owners often seek ways to maximize healing and minimize scarring, particularly when high-motion areas are involved.

“In horses, dermal injuries can be slow to heal, cause excessive scarring, and prolong a horse’s layup. In some cases, especially wounds of the limbs, proud flesh may develop in response to exuberant healing efforts,” said Catherine Whitehouse, M.S., an advisor for Kentucky Equine Research.

Medical-grade honey, fly larvae, and other strategies have been tested to speed wound healing. Most recently, Swedish researchers explored the use of irradiation with light-emitting diodes (LEDs), called photobiomodulation, in jump-starting wound repair.^* The LED used in the study features a pulsating visible red light and near-infrared (NIR) light.

“Some research shows that LEDs stimulate wound healing and decrease swelling and inflammation. With this in mind, veterinarians were hopeful that low-level light treatment could expedite wound repair in horses,” Whitehouse explained.

In this study, researchers created two circular skin wounds on the necks of eight healthy horses. One wound was treated with a combination of red light and NIR light for 4 minutes and 40 seconds on specific treatment days during the 25-day study period. The other wound on each horse remained untreated. The researchers photographed and assessed the wounds for degree of swelling using ultrasound.

Area and degree of swelling did not differ between treated and untreated wounds, prompting researchers to conclude that red light and NIR light had no clinically relevant positive effect on wound healing in horses.

All significant wounds should be examined by a veterinarian. Extensive wounds with significant blood loss or tissue damage should be considered medical emergencies.

Well-nourished horses have at their disposal the nutrients necessary for skin repair and hair regrowth. In addition to a well-rounded diet, a research-formulated biotin supplement can keep skin, coat, and hooves in optimal condition.

 *Michanek, P., T. Toth, E. Bergström, H. Treffenberg-Pettersson, and A. Bergh. 2020. Effect of infrared and red monochromatic light on equine wound healing. Equine Veterinary Journal. doi:10.1111/evj.13266.