The hock is referred to in equine anatomy texts as the tarsus and is the equivalent structure to the ankle in the human. It has many of the same structures as the human ankle but functions quite a bit differently. In the human the back of the tarsus, the calcaneus, is on the ground, as are the long bones of the foot which correspond to the cannon and splint bones of the horses rear leg. In the horse these are suspended above the ground primarily by the action of the flexors and stay apparatus.

Once lameness of the foot and ankle are ruled out with nerve blocks and if lameness cannot be identified on a physical exam, the hock is a common site of lameness in the hind limb. This article discusses the diagnosis of lameness in the hock and the various causes of hock lameness and their treatment. In many cases there are specific articles on the different types of hock lameness and links to those articles are given.

For a thorough description of the anatomy of the hock, including diagnostic anesthesia injection locations, click here.