Low Back and Lumbosacral Pain

            Low back pain is a common but sometimes difficult to diagnose problem in performance horses.  Rider complaints include:

• poor performance with hindlimb stiffness
• lack of propulsion in hindlimbs
• loss of flexibility during tight turns, jumping or dressage excercises
• lack of fluidity or timing during work
• reluctance to change leads at a canter
• assymmetric canter

The lumbosacral region is the junction or joint between the last lumbar vertebra (L6) and the first sacral vertebra (S1), or the low back and the pelvis.  It is made up of ligaments, muscles, bones and intervertebral discs that make up 5 separate joints.  These joints allow flexion and extension through the pelvis and low back.  Intervertebral disc disease, muscle or ligament tears or strains, and osteoarthritis commonly affect this area.

Signs of problems in this region may include loss of muscle tone or pain to palpation of the lower back.  However, primary lumbosacral pain may be confused with sensitivity to touch in “thin-skinned” or cold-backed horses, or with horses with hock, stifle or other pelvic pain.

A thorough physical and lameness evaluation is critical to diagnosis.  Examination of the horse under saddle while being ridden is often necessary.  Because this region lies beneath a thick layer of muscle that makes regular radiography difficult (ie, a portable X-ray unit), a combination of techniques may be necessary to visualize and diagnose lumbosacral problems.  Routine evaluation of this region involves trans-rectal ultrasound and sometimes thermography.  Nuclear scintigraphy (bone-scan) may be helpful to distinguish between low back problems and problems arising from other areas such as hocks or stifles.  Radiographic examination requires special equipment and may require general anethesia. 

Once a diagnosis has been made, treatment consists of reduction of pain and a controlled exercise program to strengthen and rebuild the low back region.  Rest is usally NOT indicated unless specifically directed by the veterinarian.  Pain reduction is managed by ultrasound-guided steroid injections, mesotherapy, and systemic anti-inflammatory drugs. 

Denoix, Jean-Marie and Virginie Coudry.  Review of Diagnosis and Treatment of Lumbosacral Pain in Sport and Race Horses.  In:  AAEP Proceedings 2005;  51: 366-373.

Henderickson, Dean A.  The Thoracolumbar Spine.  In: Stashak, Ted S, ed. Adams’ Lameness in Horses, Fifth Edition.  Philadelphia: Lippincott, Williams and Wilkins, 2002; 1053-1057.