Day after day, you battle with your horse to get the correct left bend. Or maybe the trouble comes when you ask him to pick up the right lead, push off his hind end, or stretch out into a longer stride. Instead of a willing response, all you get is resistance. You assume you’re facing a training obstacle, and you try to push both of you on through it. But if you take a moment to look beyond the surface, you might find that your horse isn’t unwilling to respond—he’s unable to respond. He simply can’t do what you’re asking because of stiffness.

Stiffness is defined as the inability or unwillingness to bend or flex as a result of an inability to stretch the tissues needed for bending to occur—in short, a reduced range of motion in the back, neck, or leg joints. But stiffness isn’t actually a disorder in itself. Rather, it’s a symptom of—and reaction to—pain or discomfort that could stem from nearly anything, including arthritis, vertebral injury, bad teeth, poor saddle fit, sore muscles, and more. This probably explains why stiffness is such a prevalent problem. It affects horses of all breeds, ages, and genders, and it crosses all lines of discipline, afflicting high-end performance horses as readily as childrens’ pleasure mounts.

In fact, Kevin Haussler, DVM, PhD, DC, of Cornell University’s Integrative Medicine Service with the Large Animal Clinic, notes that “80-90% of the horses we see in here present with stiffness, not obvious pain or lameness.”

The bad news is that it’s hard for veterinarians to measure and accurately evaluate stiffness. So, diagnosing its presence and cause becomes primarily a process of elimination (see “Finding the Cause” below). The good news is that horse owners have many treatment options at their disposal to combat stiffness once the underlying problem is diagnosed