Radiology of the equine hock and proximal cannon

Lameness associated with the hock (tarsus) and proximal cannon (metatarsus) is not uncommon in both performance and leisure horses, and radiographic evaluation is frequently indicated. In the hock, developmental orthopaedic disease predominates in juveniles, while mature animals more commonly present with degenerative or traumatic lesions. Radiographic pathology of the proximal metatarsus consists largely of traumatic injuries to the vestigial metatarsal bones and entheseous changes associated with the origin of a diseased suspensory ligament. Irrespective of the presenting complaint, a standardised, complete and accurate radiographic assessment should be undertaken where indicated. This article describes how this is best achieved and gives examples of some of the more common abnormalities encountered.