The horse’s spine runs through the top of the pelvis, where five of the vertebrae are fused together to form the sacrum. This wedge of bone is attached to the pelvis at the sacroiliac joint.
If your horse is showing hind end discomfort and stiffness, is unable to pick up or maintain canter leads, has poor low back muscle development, cannot engage or lacks impulsion, bucks or rears under saddle, the sacroiliac region may be to blame.
The sacroiliac region is a common factor in non-specific or shifting hind limb lamenesses, particularly in racehorses and sport horses, and has been the focus of recent study for better diagnosis and treatment. Sacroiliac injuries may be acute (recent) or chronic (ongoing) and may involve the bony structures of the joint (osteoarthritis) and/or the surrounding soft tissues.
Racehorses are prone to SI problems, as well as any horse who must engage these joints under significant pressure, such as the Grand Prix jumper, or the dressage horse under extreme collection (lowering the hind end to take more weight). Horses who slip in pasture, or put a hind leg in a hole or over a fence can also have tears or problems in this area.
ASSESSING THE PROBLEM
Carefully stand behind your horse and look at the top of his croup. Are the muscles and the
top of the rump symmetrical? Can you groom and rub here without your horse getting upset? Does he have any problems lifting his hind legs for the farrier? Are there any issues noted at the canter, such as bunny-hopping or trouble with one lead? Outward physical changes such as muscle atrophy or unevenness at the croup may signal a deeper problem that warrants further examination.
The sacroiliac regions may also be sore secondary to other problems such as hock arthritis, stifle pain, or an ill-fitting saddle and imbalanced riding that causes the horse to hollow its back. It's very important to have a thorough physical and lameness examination performed by your veterinarian to determine whether or not the SI areas are a primary or secondary problem.
Often a diagnosis of soreness can be made by skilled veterinary palpation, but an ultrasound examination (over the topline or trans-rectally) to check the structure of bones, tendons and ligaments in the area is important. Local anesthetic injections or “blocks” may also be utilized to localize a sacroiliac problem, though side effects are possible.
Unevenness in the tuber sacrale can suggest a torn SI ligament, but a pelvic fracture must also be ruled out in some cases. Nuclear scintigraphy (bone scan), where a radio-opaque dye is injected into the patient and then shows increased uptake in actively inflamed areas, can also be a very useful diagnostic test for localization, as well as infrared thermography.
Once a confirmed diagnosis of sacroiliac pain or injury has been made, the current treatment approaches may be supportive and non-specific. Recommendations may include ultrasound-guided local injections to ensure deposition of medications at or close to the SI joints, though some practitioners may do "blind sticks" based on external landmarks. The injections are aimed at reducing pain and inflammation, and increasing overall mobility via local corticosteroids and sometimes hyaluronic acid. However, there are active debates among veterinary practitioners as to the efficacy of these injections, and whether or not this sacroiliac pathology is really part of a larger syndrome.
Acupuncture, particularly electro acupuncture or aquapuncture (injection of a substance such as Vitamin B-12 into acupoints or local tissues), may also be very useful for sacroiliac pain or mobility problems, along with gentle spinal manipulation/motioning, or equine bodywork to obtain a more normal range of motion and release tight or sore muscles.
Chinese Herbal Medicine support such as Jing Tang Body Sore® or Tendon-Ligament®, Hindquarter Weakness®, or Equine Du Huo®, may also be helpful depending on the specific TCVM diagnosis. And there are other Eastern and Western herbal or nutraceutical products aimed at supporting ligament and tissue repair.
Shockwave therapy is also employed in some cases. Physical therapy and conditioning exercises for strengthening may prove to be most important, including hill work, training over poles on the ground and cavalettis, and hip tuck and core strengthening exercises. Any ridden work should certainly be performed in a properly fitted saddle to alleviate any back pain or pinching. In some cases general anti-inflammatories or extended periods of hand-walking or turnout for a few months in a small paddock or on flat pasture to allow the mind and body time to heal may be the treatment of choice. Unfortunately, though dependent on the degree of injury, long-term prognosis for return to previous full athletic function is currently considered poor.
While accidents and traumas cannot always be avoided, a whole horse approach including properly fitted tack, conditioning and strengthening, balanced trimming and shoeing, appropriate nutrition, range of motion and stretching, and routine veterinary care is best prevention for any injury and disease, including sacroiliac dysfunction. Don’t let SI injuries be a pain in your horse’s butt!
Joanna Robson, DVM, CVSMT, CMP, CVA, CSFT, CIT, is an integrative veterinarian and owner of Inspiritus Equine, Inc. in Napa, CA. She is dedicated to a whole horse approach and has published a book and DVD “Recognizing the Horse in Pain II - and what you can do about it.” Dr. Robson is an internationally known author, lecturer, and clinician, and she is also working to bring veterinary care to the street dogs and cart ponies of Myanmar.