laser therapy to treat soft tissue injuries in horses

Laser therapy has been a popular treatment in humans and animals since the 1960s for managing pain and healing a variety of injuries.

“While there’s a lot of debate going on about its effects, they appear to be desirable,” said Niklas Drumm, DrMedVet, Dipl. ACVS-LA, ECVS, a shareholder and practitioner at Tierklinik Lusche, in Germany. He has treated hundreds of equine patients with laser therapy at his clinic and presented the existing evidence on its efficacy at the 2018 British Equine Veterinary Association Congress, held Sept. 12-15, in Birmingham, U.K.

Most laser therapy studies have been done using low-level laser, which is popular for managing pain, healing wounds, and treating tendon injuries, said Drumm. However, he said, it’s penetration depth isn’t sufficient for treating deeper structures in horses. So he focused on what we know about high-power laser therapy, which human physicians use to treat injuries such as tendinopathies and neck and back pain in people.

Earlier this year, a team of researchers performed an in vitro (in the lab) study of high-power laser on equine mesenchymal stem cells. They found that the laser increased anti-inflammatory mediator and growth factor expression, meaning it could potentially enhance the stem cells’ therapeutic properties.

The challenge when evaluating this therapy, said Drumm, is the great variation between lasers and protocols. Results obtained with one laser device, be it low-level or high-power, don’t transfer to another. Plus, the amount of light the lasers transmit is still unknown, he said, and results vary depending on whether the horse’s skin is body-clipped, dry, etc.

Drumm said he started using high-power laser therapy in his clinic in 2013 after consulting with sports medicine physicians that use this therapy to treat muscle and tendon injuries in elite human athletes. He chose a 15W diode laser that emits four wavelengths of light simultaneously (635 nm, 660 nm, 810 nm, 980 nm) and was immediately impressed by its results in horses with tendon injuries.

“We could return horses to low-level and ultimately full performance much faster than with other treatment modalities,” said Drumm.

laser therapy to treat soft tissue injuries in horses

To fully evaluate the laser’s effects, the group at Tierklinik Lüsche studied 150 Warmblood sport horses treated at their clinic for acute or chronic superficial digital flexor tendonitis or suspensory desmitis. The horses received high-power laser therapy daily for two weeks. Each treated limb was clipped and degreased with alcohol before treatment, and the team performed follow-up clinical and ultrasound exams four weeks later.

They found that:

  • All horses improved in lameness score, with 80% sound at four weeks post-treatment.
  • On ultrasound, 76% showed only mild or no abnormalities after treatment.
  • The median time to return to low-level exercise was six weeks.
  • 55.8% had returned to their previous level of performance within six months.
  • Reinjury rate after one year was 21%, which he said is comparable to other treatments.
  • There were no complications.

“We concluded that high-power laser with this device is safe, results in fairly low reinjury rates, and has a fairly quick return to performance,” said Drumm. “We have now treated 1,070 horses with it since 2014.”

Drumm and Tierklinik Lüsche colleague Mathilde Pluim, DVM, also just wrapped up a placebo-controlled study on 12 horses with surgically created suspensory branch lesions treated with the same laser device, and the preliminary results are promising, he said.

He added that while laser therapy with this device appears to be safe and efficient for treating soft tissue lesions in horses, we can’t extrapolate results between machines.