Light Therapy — Wound Healing in Horses
LED light therapy is really a way to help the body heal itself. In Kaiyan, we have used specific wavelengths of light absorbed by a photo acceptor, cytochrome c oxidase, within the cell's mitochondria. The energy (photons) from the lights increases the energy within the cell, which speeds up the healing process. The lights must be specific wavelengths and must be delivered at a specific dosage. We use two wavelengths in our light therapy pads, a visible red and a near-infrared wavelength. Using both red and near-infrared lights is beneficial because different depths of tissue absorb the wavelengths. The combination of the two work in concert to provide benefits for soft tissue injuries, inflammation, ligament soreness, tendon problems, sore backs, splints, strains, stifle issues, sprains, swelling, shoulder pain, hip pain, sore backs, sore necks, salivary gland problems, wounds, cuts, scrapes, arthritis pain and for trigger points and acupuncture points. Visible red light (660nm) is absorbed by skin layers very efficiently and best for uses such as stimulating trigger and acupuncture points and treating wounds and infections. Near-infrared light (850nm) penetrates to a deeper level has been used to treat concerns of tendons, ligaments, bones, joints, and muscle.
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 the 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 horses' wound healing.
A veterinarian should examine all significant wounds. Extensive wounds with significant blood loss or tissue damage should be considered medical emergencies.
*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/eve.13266.