Withers

The withers is the highest point on a horse's back, on the ridge between its shoulder blades. The height of a horse is measured from the ground to the withers because that is a fairly stable and predictable height when the horse is standing still. Unlike humans, whose heads are in a fairly fixed position when standing upright and looking forward, a horse can move its head easily into a wide range of positions when standing still, so it makes a poor location for measuring the animal's height.

The equivalent point on other four-legged domestic animals, such as dogs, is also called the withers and is also used to measure the animals' height.