But in many cases, veterinarians can treat and rehabilitate the injured joint and return the horse back to work. It just takes some time, dedication, and a bit of good luck. At the 2016 American Association of Equine Practitioners Convention, held Dec. 3-7 in Orlando, Florida, Steve Adair, DVM, MS, Dipl. ACVS, ACVSMR, CERP, reviewed the methods veterinarians can use when rehabilitating equine joint injuries.
There’s not one “shotgun” approach when developing and implementing a rehabilitation plan, said Adair, an associate professor at the University of Tennessee College of Veterinary Medicine, in Knoxville. There is, however, one thing that every rehab program needs: a dedicated team.
“Rehabilitation is a team approach consisting of the veterinarian, therapist, owner, as well as other professionals,” he said. “All members of the team need to be informed and on board to ensure the best possible outcome.”
Know the Injury
An accurate diagnosis is key to planning a successful treatment and rehabilitation. Also important is knowing what stage the injury is at, Adair said, as different stages have different treatment goals.
“The initial stage is from the time of injury or surgery until all inflammation has resolved,” he said. In this stage, focus on decreasing pain and inflammation, preserving the joint’s range of motion, and preventing muscle atrophy (wasting).
“The second stage starts when inflammation is resolving or resolved,” Adair said. “During this stage, you need to gradually increase the stress that the healing tissues are subjected to. You are trying to prevent scar tissue from developing or revising it.”
It’s also important to monitor the injury as it heals, he said, noting that this can be accomplished using some inexpensive and easy-to-use equipment.
“Try using quantifiable methods,” he said. “For instance, tape measures may be used to measure limb circumference, goniometers can be used to measure joint angles, and pressure algometry may be used to measure decreasing pain in an area.”
Of course, diagnostic imaging and objective lameness evaluation can be used, as well.
Know Your Options
Equine rehabilitation has come a long way since the days of only stall rest and hand-walking. While these treatment mainstays are still important for helping a horse return to health, veterinarians today have a variety of other options at their disposal, as well.
Massage, stretches, and mobilization, oh my. Veterinarians use these methods to help restore range of motion to joints in either acute or chronic injuries. On the whole, Adair said, manual therapies help restore optimum joint movement.
Adair said massage and stretching help increase blood flow, reduce muscle spasms and scar tissue, and promote lymphatic drainage. Further, both can relieve muscle and nerve pain, restore muscle length, and improve stiffness caused by lack of movement.
Likewise, veterinarians use joint mobilization to relieve pain and restore normal biomechanical, nerve, and muscle function, he said. There are two types of mobilization: passive and active. Passive mobilization involves the practitioner moving a joint to the end of its normal range of motion, then passively flexing and extending the limb, only to the point where resistance is met. Active mobilization involves the horse moving a joint as far as it can, typically to retrieve a treat (you might know this practice better as carrot stretching).
Cold and Heat
Cold and heat therapies have long been mainstays of equine rehabilitation, and they remain useful tools in the veterinarian’s arsenal.
“The main benefit of cold therapy is to decrease circulation, lower cell metabolism, prevent secondary damage, decrease edema (fluid swelling), and decrease pain,” Adair said. “The primary effect is to constrict blood vessels. This reduction in blood flow reduces edema, hemorrhage, and extravasation of inflammatory cells (inflammatory cells essentially leaking into nearby tissues). The lower cell metabolism decreases the effect of inflammatory mediators and slows enzymatic systems.”
Cold therapy, which Adair said is most useful in the immediate phase following injury or surgery, can be applied in a variety of ways, including cold-water emersion, cold or ice packs, salt water spas, and ice water circulation boots.
Conversely, heat therapy is more useful after the acute phase of injury and can increase circulation, muscle relaxation, and tissue pliability, Adair said. “When tissue blood flow is increased, metabolites are mobilized, oxygen levels are increased, and the metabolic rate of cells and enzyme systems are increased,” he said, which can promote edema resorption.
Despite those differences, heat can have similar results as cold therapy, Adair added.
“Heat can also decrease pain via similar mechanisms to cold therapy,” he said. “Tissues are more effectively stretched after warming, and heat therapy can be used to increase joint and tendon mobility.”
Apply heat carefully, however. “Most of the physiologic effects of heat occur when tissue temperatures are raised to between 40 and 45ºC (104 and 113ºF),” he said, and heat must be applied consistently for 15 to 30 minutes. However, he added, “tissue temperatures above 45ºC may result in tissue damage.”
Veterinarians can use low-level laser therapy (LLLT) to stimulate the horse’s bodily responses, Adair said. It’s been reported to have many effects, including:
- Promoting waste removal;
- Reducing repair time;
- Relieving swelling;
- Aiding in skin wound repair;
- Stimulating the circulatory and lymphatic systems;
- Increasing serotonin in the blood; and
- Biostimulating effects, which is purported to provide some chronic pain relief.
“In our practice, the most common use of LLLT is to decrease pain and inflammation associated with musculoskeletal injuries and for wound healing,” Adair said.
Your veterinarian might have performed an ultrasound examination when diagnosing your horse’s injury, but he or she can also use ultrasound waves to help the healing process.
“Therapeutic ultrasound is a form of acoustic energy used to treat musculoskeletal injuries,” Adair said. “It offers deeper heating without excessive heating of the skin.”
Veterinarians use therapeutic ultrasound with goals such as:
- Decreasing pain;
- Reducing muscle spasm;
- Encouraging wound healing;
- Hastening hematoma resorption;
- Reducing swelling;
- Decreasing scar tissue formation;
- Increasing blood flow to the affected area;
- Enhancing collagen extensibility, remodeling, and production; and
- Improving range of motion.
Few studies on therapeutic ultrasound’s impact on horses have been conducted, and those that do exist have yielded varying results. Adair said his practice has found this modality most useful for heating tendons and ligaments prior to exercise or mobilization.
Don’t discount the usefulness of targeted exercises for helping horses with joint injuries recover. Exercise such as hand-walking, riding, work over ground poles or varying terrain, underwater treadmill use or swimming, or even pasture turnout can be beneficial in some cases. Always get your veterinarian’s nod of approval before beginning or increasing exercise, however—too much work too soon can have negative effects on your horse’s recovery.
“The goal of therapeutic exercise is to provide a gradual return to function and improve strength and coordination,” Adair said.
Ground exercises (such as walking over poles or working on hills) can take place with the patient in-hand, under-saddle, or ponying alongside another horse. These exercises are typically used to target a specific concern, Adair said, such as improving proprioception (the horse’s awareness of his body’s position and movements, including limb and foot placement) or improving joint mobility. Some examples:
- Working over ground poles placed in varying patterns (for instance, in a straight line; in a wagon-wheel-spoke pattern; or placed randomly) and heights;
- Transitioning from surface to surface (i.e., sand to grass to water to asphalt);
- Exercising while wearing therapeutic bands to improve core muscle stability;
- Pulling a cart; or – Working up and down hills.
Aquatic exercise such as “swimming and underwater treadmills may provide several benefits,” Adair said. “Their use allows the horse to maintain cardiovascular fitness and muscle tone and improve joint movement without undue stresses on the injured limb. … In addition, they provide a different type of muscle exercise and work different groups of muscles than when working on land.”
A few important points regarding aquatic therapy:
- Horses must be acclimatized to the swimming pool or water treadmill before conditioning begins;
- Pay attention to the water temperature. For active exercise, such as swimming, use 65-82$deg;F water, Adair advised. Water for less vigorous exercise can be 96-104$deg;F;
- While not all facilities monitor specific fitness parameters for horses during or after exercise, he recommended at least measuring horses’ heart rates and blood lactate levels. Heart rate can help indicate how much stress is placed on the cardiovascular system, and lactate levels can help determine whether the horse is working hard enough to achieve conditioning; and
- Do not use aquatic exercise on horses with acute joint inflammation, skin infections, open wounds, acute myositis, cardiovascular issue, or respiratory disease, Adair said. Swimming is not recommended for horses with upper limb lameness or back pain.
Back to Work
“At some point the rehabilitation program will end and the horse will be returned to work, if possible,” Adair said, adding that this must be carried out gradually. “Although the particular injury may have healed, the rest of the body may not be in condition.”
He recommended spending at least 10 minutes warming up and cooling down for each ride and gradually increasing the amount of work the horse does with veterinarian approval.
“It is important to determine whether the injury has healed sufficiently to allow for increased stress prior to progressing,” he cautioned.