The unfortunate diagnosis of “navicular disease” has resulted in the demise of considerable numbers of horses worldwide. Yet improved and higher standards of farriery and veterinary care in recent years have elevated horses to a higher level of soundness than in the past.
Along with improved levels of soundness, we now have the ability to spot lameness concerns much earlier. As a result, an experienced or observant horse person, vet or farrier will often see problems associated with pain in the caudal parts of the foot up to 2 years prior to diagnosable lameness.
Some authors have labeled this time as a “pre-navicular syndrome,” or a pre-lameness period. During this time, you may be able to see changes in shoe wear, an unevenness or lack of levelness in the gait at the start of a horse’s work that eventually warms up and becomes level once more. Many farriers have also seen other changes in behavior that are indicators that the horse is uncomfortable.
The greatest challenge is the fact that there is no perfect distal sesamoid (navicular bone). Yet there are a broad range of situations that are considered normal, which complicates diagnostic outcomes.
While the exact cause is unknown, it is likely to be multifactorial involving the distal sesamoid (navicular bone) and its blood supply. The suspensory ligaments, distal phalangeal joint (coffin joint) and their collateral ligaments, navicular bursa, deep digital flexor tendon (DDFT) and the impar ligament all play a part in…