Back problems in horses are not new, but advanced diagnostic tools are helping veterinarians diagnose them more frequently. Some assessments suggest that up to 94% of ridden horses experience some degree of back pain. Owners might notice their horse becoming reactive when they tighten the girth or angry when they sit the trot. Other complaints are less specific: The horse isn’t feeling right, performance has diminished, or other behavioral issues have surfaced. Veterinarians often notice horses guarding their painful backs. Sometimes, diffuse back pain is present. It is also not unusual for horses to experience concurrent lameness issues.
At the 2024 American Association of Equine Practitioners Convention, Katie Ellis, DVM, MS, DACVSMR, of the University of Georgia, presented strategies for managing and rehabilitating painful equine backs. She describes a cycle of pain and dysfunction: Underlying pathology is often accompanied by structural changes that then elicit a protective reflex to inactivate the multifidus muscle. This is significant because the multifidus muscles, adjacent to the spinous processes and spanning up to five vertebrae, are the major postural and stabilizing muscles of the spinal column.
The multifidus muscle atrophies with diminished use and can become infiltrated with fat, making it harder for the muscle to do its job. The resulting destabilization of the spine causes the longissimus muscles, sitting lateral to the multifidus, to take over the job of stabilization. With the added workload, the longissimus muscles fatigue, leading to an ongoing cycle of dysfunction and pain.
Ellis described important goals for rehabilitating horses with back pain. The first goal is to break the pain cycle, which is the most challenging part of treatment. Other goals include restoring flexibility and reestablishing neuromotor control from the brain telling the muscles and body to move. Another important rehab goal is to promote strength and endurance to rebuild the multifidus and longissimus muscles. By restoring normal function, pain decreases, stopping the dysfunctional cycle.
So, how to break the pain cycle? Ellis listed various modalities to help with this objective.
Pharmaceutical Options
- With ultrasound guidance, local substances can be injected into the interspinous space within the interspinous ligament or adjacent to kissing spines.
- When there is no osseous pathology, medication or mesotherapy can be injected directly into the epaxial muscles.
- Corticosteroid injections are cost-effective.
- Systemic medications like gabapentin or methocarbamol (if back pain is diffuse) might help, but beware withdrawal times for competition. Prednisolone is useful to rule in or out behavioral issues under saddle. Administer with a progressively weaning dose over three to four weeks to determine if bad behavior is related to axial pain.
- Bisphosphonates.
- A trial of non-steroidal anti-inflammatories (NSAIDs), which Ellis said do not usually mitigate axial pain.
Nonpharmaceutical Options
- Extracorporeal shock wave therapy provides analgesic and healing stimulating effects.
- In studies comparing chiropractic, massage, and phenylbutazone, chiropractic was best at improving the pain threshold with phenylbutazone eliciting the least response.
- In one study, horses receiving electroacupuncture had less pain than control and phenylbutazone groups. However, Ellis noted that acupuncture is difficult to use in horses with moderate or severe back pain.
- Elastic therapeutic taping (i.e., kinesiology tape) lifts the skin to increase circulation to the subcutaneous tissues. Tapes can be applied as myofascial or trigger release patterns. In a crossover study comparing kinesiology tape to sham tape, the kinesiology tape increased pain thresholds significantly.
- BEMER (pulsed electromagnetic field therapy, or PEMF) is a bioelectromagnetic energy regulation blanket. In one study, after wearing the blanket twice daily for three days, horses had reduced back pain, improved postural control, and improved spinal flexibility. Ellis said it is tricky to extrapolate these results to other PEMF devices because each product uses different frequencies and pulse widths.
- Thermotherapy/Cryotherapy
- Heat therapy with a heating pad or solarium reduces muscle spasms and increases flexibility and blood flow. Therapeutic ultrasound produces no significant heating effect of epaxial back muscles because it cannot penetrate past a few centimeters.
- Radiofrequency diathermy: A few cases showed positive improvement measured subjectively, but another study of 20 horses did not find any effect on pain either subjectively or objectively.
- Cryotherapy with ice packs or cold-water spa reduces inflammation and pain.
- Mechanical nociceptive thresholds (MNTs) provide an objective measure of pain thresholds by applying a pressure algometer at specific locations until the horse exhibits a withdrawal response such as splinting the back, moving away from a stimulus, pinning ears, or trying to bite. The higher the number measured, the less pain, because more pressure is required for the horse to respond.
Strengthening Exercises
After breaking the pain cycle, it’s time to move forward with other goals, which Ellis said can be targeted simultaneously.
Foremost is the use of physiotherapy exercises to restore flexibility, reestablish neuromotor control, promote core strength, and further reduce pain. Ellis recommended implementing these exercises after a horse is worked, when the muscles are warm and most flexible. Some horses benefit from doing these exercises before and after exercise:
- Sternal lifts, lumbosacral tucks, or a combination of the two.
- Caudal tail pulls.
- Lateral bending.
- Ventral flexions.
- Back wiggles.
Physiotherapy exercises are shown to increase the multifidus muscle’s cross-sectional area, with some reports indicating they help horses return to work faster after colic surgery.
Elastic resistance band (Equiband) training restores flexibility and promotes proprioception, muscle strength, and endurance. One study demonstrated increased dynamic stability through the thoracolumbar region after four weeks, but other studies do not provide overwhelming evidence for muscle activation with this device. More research is needed.
Underwater treadmill work restores flexibility, increases core strength and endurance, and restores neuromotor control and postural stability. The resistance of walking through water helps with these goals and achieves them with minimal impact. Water depths up to the stifle stimulate increased thoracic extension and thoracolumbar flexion.
Proprioceptive balance pads reestablish neuromotor control and promote strength. The pads come in different firmness levels, with soft pads making it more difficult for a horse to maintain balance. A study using these pads for five minutes twice daily five days a week for four weeks showed significantly improved postural sway and increased multifidus cross-sectional area.
Whole body vibration therapy reestablishes neuromotor control and promotes strength. In humans, it improves muscle strength and postural stability and reduces pain perception. Vertical plates seem to work better than horizontal plates, said Ellis. She reported on a study of horses with marked thoracolumbar pain that received vibration therapy 30 minutes once a day, five days a week for 30 days. Pain thresholds were measured before and 24 hours after the first session and at Days 14 and 30. In the first 14 days, the pain threshold worsened but then improved significantly by Day 30. Postural sway and the multifidus cross-sectional area improved by the end of the study. She stressed that vibration therapy must be used consistently over time to achieve results.
Pole work is helpful to restore flexibility, reestablish neuromotor control, and promote strength. Ellis recommended walking over ground poles to activate rectus abdominus and longissimus muscles. Trotting over ground poles activates multifidus muscles. Cavalettis improve proprioception and motor control. Walking in serpentines between ground poles or barrels improves lateral motion and flexibility.
Final Thoughts
Ellis stressed that a multimodal approach is important to break a horse’s pain cycle. You can then start building core strength and fitness. Combining the various techniques helps provide relief from back pain in affected horses.
Related Reading
- Important Elements of Saddle Fit Veterinarians Should Know
- Diagnostic and Treatment Modalities for Overriding Spinous Processes in Horses
- Equine Lumbosacral Pathology and Back Pain
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