DSMD (Idiopathic Hopping): A Commonly Missed Cause of Front-End Pain in Horses

DSMD—often referred to as idiopathic hopping—is an underrecognized source of front-end pain in horses. Rather than originating in the lower limb, DSMD is associated with dysfunction of the scapular and thoracic sling, the muscular system responsible for suspending the horse’s trunk between the forelimbs. When this system is painful or compromised, normal movement can become uncomfortable or even alarming for the horse.

Why DSMD Is Often Missed

Because there may be no obvious limb lameness, horses with DSMD are frequently mischaracterized as behavioral, anxious under saddle, or simply “tight in front.” Symptoms may fluctuate and worsen with work, tack pressure, or poor saddle fit—further obscuring the underlying cause.

A horse with idiopathic hopping / DSMD before treatment, followed by the same horse after intervention—showing improved rhythm, symmetry, and overall movement quality.

Common Signs to Watch For

Horses with DSMD may show one or more of the following:

• Girthiness or sensitivity during tacking

• Anxiety or resistance when the saddle is placed

• Short, choppy, or restricted front-end stride

• Intermittent “hopping” or stabbing steps in front

• A wide or braced front-leg stance at rest

• Sensitivity around the withers, shoulders, or scapula

These signs are especially concerning if they appear suddenly, worsen with work, or fail to resolve with rest or routine bodywork.

The Role of Tack and Fit

Poorly fitting saddles, narrow trees, inadequate padding, or excessive pressure over the withers and scapula can exacerbate thoracic sling pain. In some cases, tack-related pressure is the tipping point that brings previously subclinical discomfort to the surface.

Diagnosis and Treatment

DSMD is treatable, but accurate diagnosis is key. A veterinary evaluation is essential to rule out other sources of pain and to identify thoracic sling involvement. Early intervention improves outcomes and helps prevent secondary compensation patterns in the neck, back, and forelimbs.

How Kinetic Equine Medicine Can Help

At Kinetic Equine Medicine, we work collaboratively with veterinarians to identify and treat complex sources of front-end pain, including thoracic sling and scapular dysfunction. If you’re seeing these signs in your horse—or if something simply doesn’t feel right—early evaluation matters.

If the issue is new or not improving, contact your veterinarian. To schedule a consultation with Kinetic Equine Medicine, please email us to begin the process.

Educated eyes catch pain earlier—and early care makes a meaningful difference.