Rehabbing Soft Tissue Injuries in Horses

“Prevention is the best treatment” for any horse health issue, said Andris J. Kaneps, DVM, PhD, Dipl. ACVS, ACVSMR. “But we all know that we can put a horse in a padded room, wrapped in bubble wrap, and we’ll still have issues that we’ll need to address.”

Yes, horses are incredibly skilled at injuring themselves, and some of the most common ailments include soft tissues like tendons and ligaments. That’s why veterinarians must be well-versed at treating and rehabilitating such issues.

At the 2016 American Association of Equine Practitioners Convention, held Dec. 3-7 in Orlando, Florida, Kaneps, who owns Kaneps Equine Sports Medicine and Surgery, in Beverly, Massachusetts, reviewed best practices for rehabilitating soft tissue injuries.

In a healthy tendon or ligament, “there are even, organized fiber patterns,” he said. “When the injury occurs, the fibers tear, hemorrhage, and go through an inflammatory process. The goal with treatment is to take the problem area and return it to a normal structure.”

First Aid

The first step is recognizing that there’s a problem, he said, which is often evidenced by pain, swelling, and response to palpation.

Then comes the most important step: Stop the horse from exercising.

“This can be challenging for a mild swelling that turns up at a big competition, but we have to put the brakes on,” Kaneps stressed.

The next goal should be to reduce inflammation in the affected area, which will make it easier to diagnose. He suggested using cold therapy (more on this in a moment) and/or non-steroidal anti-inflammatory drugs (NSAIDs). Additionally, apply a support bandage to keep the injured area stable.

Kaneps said to aim to reach a diagnosis within a day or two of when the injury appears. With soft-tissue injuries, ultrasound is often the most useful imaging modality. He encouraged attendees to record outcome measures (such as lameness grades and tissue dimensions) at all exams, as these can help track the horse’s progress.

Rehabilitation Techniques

Once you’ve reached a diagnosis, it’s time to begin rehabilitating the injury. Kaneps reviewed several options veterinarians can use in concert to help achieve the best result possible.

Cold therapy

One of the simplest measures is also one of the most effective at helping tissues heal. Kaneps said the optimal tissue temperature to reach during cold therapy is 59-66 degrees F (15-19 degrees C). The gold standard for cold therapy is ice water immersion, he said—soaking the injured area in an ice and water slurry. It takes 10 to 13 minutes to reach the thermal plateau (the coldest the limb will become), and the total soaking time should be 20 to 30 minutes. Study results have shown that ice water immersion can cool the deep tissue in a horse’s limb by up to 16 degrees C.

He recommended repeating cold therapy three to four times per day for the first 48 hours after acute injury and continuing treatment two to three times per day for about two weeks. He also said owners can use cold therapy following exercise when the horse returns to work to reduce inflammation at the injury site.

Kaneps said ice and cold packs can be useful, but they tend not to be as effective as ice water immersion. Salt water spas can also help.

Controlled exercise

“This is the primary, most effective treatment,” Kaneps said. “Everything else is just icing on the cake.”

He said studies have shown that horses treated using controlled exercise had a successful outcome in 67-71% of cases, while just 25-51% of horses treated with pasture turnout had a successful outcome.

Kaneps encouraged practitioners to begin hand-walking horses shortly after the injury because tendons and ligaments require a bit of stress to help properly. The rule of thumb, he said, is to increase exercise by 5-10% each week and reassess lameness and ultrasounds every 60 to 90 days.

While each horse’s regimen should be tailored to his individual situation, Kaneps said many controlled exercise programs go something like this:

  • Gradually build up to hand-walking for 30 minutes two to three times per day;
  • Then, transition to walking under tack for 20 to 25 minutes per day;
  • After about two weeks, add three to five minutes of trot per day; he stressed that horses shouldn’t be trotted until the horse is warmed up at the walk for 10 to 15 minutes;
  • Increase the trotting time gradually to 20 to 25 minutes per day;
  • Then, add three minutes of canter, gradually increasing that time.
Rehabbing Soft Tissue Injuries in Horses

The veterinarian should recheck the horse’s lameness before each workload increase, he added.

Regenerative treatments

In many cases, rest, controlled exercise, and cold therapy can provide a successful outcome. But some regenerative therapies can improve or shorten the healing process. Options include:

  • Platelet-rich plasma (PRP) delivers a high concentration of platelets in the form of blood plasma to a lesion, increasing the amount of growth factors at the site to help the injury heal. There are commercially available PRP products, along with a stall-side system that separates the horse’s own red and white cells from the plasma in a relatively short amount of time. The veterinarian injects the PRP directly into the lesion or to multiple areas immediately surrounding the lesion to help healing.
  • There are two main types of stem cells: bone marrow-derived and adipose (fat)-derived. Kaneps said stem cells enhance matrix production and recruit growth factors to help the injured areas heal with better quality, strength, and elasticity. He said one study showed a lower reinjury rate in horses with soft-tissue injuries treated with stem cells than those that did not receive stem cells.

Kaneps said the optimal time to inject both PRP and stem cells is three to four weeks following injury, and it’s best to inject under ultrasound guidance. After the injection, he said, stop exercise and keep the injured limb bandaged for about two weeks. The veterinarian should follow up four weeks after injection.

Veterinarians use another regenerative therapy, IRAP (interleukin-1 receptor antagonist protein), more frequently in joint injuries than in soft-tissue injuries.

Therapeutic ultrasound

Kaneps said this treatment can help relieve pain and improve healing in multiple ways. First, he said, it stimulates healing by delivering heat to the injured tissue, which increases local circulation, among other effects. Additionally, it can improve collagen disposition and wound contraction, he said.

He also noted that, with proper training from the veterinarian, horse owners can perform therapeutic ultrasound on their own horses if they rent or purchase a unit. Treatment is administered once daily for two to four weeks.

Rehabbing Soft Tissue Injuries in Horses
Extracorporeal shock wave therapy (ESWT)

Many veterinarians also use ESWT to treat soft tissue injuries. Kaneps said it has been shown to reduce inflammation; increase cytokines, growth factors, and osteoblasts (all important to the healing process); and might recruit stem cells to the affected area.

He said treatment should begin seven to 14 days after injury and should be followed by two days of stall rest without hand-walking. Repeat treatments every two to three weeks for three to five treatments, he said, and maintain 10 to 15 minutes of hand-walking throughout treatment. The veterinarian should reevaluate the horse two weeks after the third treatment and decide whether to continue or change the treatment method.

Kaneps cautioned that tissue damage can occur if you use a setting that emits too much power, so use an appropriate energy flux.

Laser therapy

Finally, he touched on laser therapy. While there have been many recent advancements in laser therapy, Kaneps said there’s still no research proving that it’s effective for treating soft-tissue injuries.

Still, he said modern lasers could have sufficient energy and penetration depth to be effective at reaching and providing energy to the cells involved. Acute injuries can be treated daily, and chronic ones should be treated every two to three days, he said.

Take-Home Message

Kaneps wrapped by reminding attendees that successful treatment depends on an accurate diagnosis and good knowledge of the therapeutic options available. He also encouraged them to keep detailed records of outcome measures to monitor progress.