Sacroiliac pain in horses is a performance limiting condition that can be challenging to diagnose and manage. To understand why horses, develop this problem we first need to understand the anatomy involved.
The pelvis is a ring of bones formed of three fused bones; Ilium, ischium and pubis. The lower part of the horses back, the sacrum, is formed of 5 fused vertebrae. The sa
croiliac joint (SI) is the joint where the sacrum passes underneath the top of the pelvis (tubera sacrale). The Sacroiliac joints have minimal movement, and are supported by strong ligaments around the pelvic area, which are important in stability. There are three main ligaments that support the area, these are the dorsal and ventral sacroiliac ligaments, and the sacrotuberous ligament. SI pain is either in-flammation of the joint or ligaments surrounding the joint. The SI joint functions to transfer energy from the hind limb through to the horse’s spine, supporting the horses back and driving the horse forward from its hindquarters when in motion.
SI pain typically affects heavier, taller horses usually between the ages of 5 and 15 years old. However, there is no documented association between a horse’s confirmation and developing SI problems. Damage to the sacroiliac joint usually occurs because of one of two main reasons:
As a result of direct injury to the area due to a trauma, fall or slip causing damage to one or more of the supporting ligaments. In some cases, a fracture to the pelvis can cause secondary damage to the joint.
Abnormal movement of the hind limbs usually associated with either lameness issues such as hock osteoarthritis or suspensory ligament problems. Abnormal movement in the hind limbs causes stress and instability in the SI joint resulting in arthritic changes, inflammation and pain.
The signs that a horse maybe suffering from SI pain are subtle and insidious in onset and progression. Usually the symptoms are exacerbated when the horse is ridden under-saddle and can be easier to appreciate by the rider than to be seen by an observer, as not always an overt lameness to be seen. Often it begins with a lack of forward propulsion, or simply poor performance. The canter is the most affected gait, and the horse may have problems with strike off or maintaining a particular canter lead. Discomfort to the SI joints leads to muscle loss particularly over the medial gluteal or rump area. This muscle loss can create the appearance of a hunter’s bump as the tuber sacrale become more pronounced. It is important that a correct diagnosis is found, and that other underlying issues are eliminated.
Typically, the signs are:
Poor performance / unwillingness to work
Stiff through the back / refusing to jump.
Lack of impulsion
Reluctance to “round” over the back
Poor lateral work
Reluctance to canter / disunited / taking the wrong lead
Tuber sacrale, or “Hunter’s Bump” becomes more prominent due to reduced gluteal muscle mass
Pain on motion palpation over pelvic area
Painful muscle spasm particularly lumbar back musculature
Assymmetry over pelvic area / muscle loss
Reluctance to be shod or have the leg held in a flexed position for a prolonged period of time
Once a formal diagnosis has been made by a veterinary surgeon a treatment plan usually involving a combination of medication, physiotherapy and a rehabilitation programme can begin. Typically, the SI region can be injected with steroids to reduced inflammation of the joint and ligaments. This will be performed by your veterinarian when required and usually requires more than one treatment.
Physiotherapy and rehabilitation are important in making sure the horse works to build up strong muscles around its hind quarters so the SI region is protected and used correctly. The aims of physiotherapy are to encourage symmetrical development, improve core stability, strengthen the surrounding musculature, relieve muscle spasm and re-educate neuromuscular pathways. Each horse with a diagnosed SI condition will have a tailored rehabilitation program outlining the details of exercises and time period. In feed, anti-inflammatories or joint supplements may be beneficial in reducing in-flammation and promoting healthy joints.
It is important that each case is treated on an individual basis in order that the appropriate treatment and exercise program is followed.
For information on how physiotherapy, mobilisations, manual and electrotherapies can help, contact Leaps and Bounds Veterinary Physiotherapy for further details.