Prognosis for Cow Hocks

Q.  I recently purchased a young horse that is cow-hocked. The conformation fault isn’t severe, but he’s not perfect. He’ll start training next year. Should I be concerned about athletic pursuits with him?

A. Stand your horse up square on a flat surface, then stand directly behind him and look at his hind leg angles. If he angles outward from the fetlocks only, he’s not cow-hocked but instead is toeing out. But if his hocks sit close together and angle inward, and his fetlocks reach farther out than his hocks, he’s cow-hocked.

Cow-hocked conformation is known technically as “tarsus valgus,” which is one type of angular limb deformity. Many draft horses have this conformation characteristic as a standard part of their breeding program, but it is less common in light horse breeds.

The problem with any angular limb deformity is that the leg’s bony column doesn’t line up, so the limb’s ability to handle loading forces is compromised. Subsequently, there is some twist and torque placed on a less straight leg. This affects the joints and soft tissue structures because one side of the leg bears more force and weight than the other.

In mild athletic pursuits, most of the time this conformation fault doesn’t cause too much of a problem. But with a more significant angular limb deformity, or with increasing levels of athletic effort—or age—this conformation can lead to osteoarthritis in the hock joints. It is a good idea to have your veterinarian do routine evaluations on your horse’s soundness in order to identify subtle lameness issues early on so steps can be taken to minimize joint injury.

Expert: Nancy S. Loving, DVM, is a performance horse veterinarian based in Boulder, Colo. She is also the author of All Horse Systems Go.