What the research shows, and where it stops

A review of light treatment in horses, dogs and cats covering literature published between 1980 and 2020, carried out at the University of Tennessee and the Swedish University of Agricultural Sciences. Forty-five articles met the inclusion criteria, twenty-four of them concerning dogs, one concerning cats and the remainder horses. The review found conflicting results and no consensus on treatment protocols, attributing much of that to the wide variation in wavelength, dose, frequency and duration between studies, and it judged the scientific quality of the papers limited, with a high or moderate risk of bias throughout.

This is the most useful single source on this page for anyone wanting to assess the field rather than a product.

A randomised clinical trial in 61 competing Quarter Horses assessed as having back pain. Low-level laser therapy produced significant reductions in back pain, epaxial muscle hypertonicity and trunk stiffness, while chiropractic care alone did not produce significant changes in those measures, and the combination appeared to add something neither achieved on its own.

The probe used four 810 nm laser diodes with a total optical output of 3 W, which is well above what any LED system delivers. We cite this as the strongest equine trial of light treatment for back pain that we know of, rather than as evidence about our own systems.

A randomised, blinded, controlled study in eight healthy horses, with a wound created on each side of the neck, one treated and one left as an untreated control. The study found no clinically relevant effect on wound healing compared with no treatment.

It used pulsed light at approximately 637 and 956 nm, which differs from the continuous 660/670, 730, 810 and 850 nm in our systems, and experimental wounds on healthy skin are a narrow test. Neither observation cancels the result, and it appears here because leaving it out would misrepresent the state of the evidence.

A randomised, placebo-controlled study in humans. Compared with placebo, the LED group showed improved pressure pain threshold for muscle tenderness between 48 and 96 hours after exercise, together with better recovery of joint range of motion.

At 830 nm this sits close to the 810 and 850 nm in our infrared straps, which makes it one of the more directly relevant studies here, although it was carried out in people rather than horses.

A review covering mechanism and clinical application, including the concept of the optical window, roughly 650 to 950 nm, the range of wavelengths that travel usefully into tissue rather than being absorbed at the surface. That reasoning is the basis for our choice of 660/670, 730, 810 and 850 nm.

A laboratory study in rats reporting reduced oedema formation and reduced migration of inflammatory cells at both wavelengths. This is animal laboratory work rather than clinical equine work, and it is included for the wavelength comparison rather than as evidence of a clinical effect.

Laboratory work on bacterial resistance following repeated exposure at 405 nm. Alongside the fact that blue light is absorbed almost entirely at the surface, this formed part of our reasoning for leaving it out of our systems.