The horse's lower limb has complex anatomy and is subject to a multitude of injuries. | Photo: Erica Larson

The next time your horse develops foot pain, you might want to think outside the box when deciding what you think is causing the problem. While common ailments such as navicular disease, laminitis, or hoof abscesses are possible, they’re not the only things that could be causing your four-legged friend pain. The distal (lower) aspect of the horse’s limb, from the mid-cannon bone down to the sole, has extremely complex anatomy and is subject to a multitude of injuries that can baffle even the most veteran veterinarians.

“It used to be that any horses with foot pain that were chronically lame and did not have signs of laminitis were diagnosed with navicular disease or a ‘catch-all’ phrase, palmar foot pain,” explained Sue Dyson, MA, Vet MB, PhD, DEO, FRCVS, head of clinical orthopaedics at the Animal Health Trust (AHT) Centre for Equine Studies, in Newmarket, England. “With advances in technology, especially magnetic resonance imaging, we are now better able to pinpoint the exact cause or causes of foot pain.”

In addition to the navicular bone, potential causes of foot pain include the deep digital flexor tendon, the collateral sesamoidean ligament of the navicular bone, and the distal sesamoidean impar ligament (the latter two of which make up the podotrochlear apparatus), among other structures