Historically, navicular disease, defined as degeneration of the navicular bone and its associated structures, was assumed to be pain localized to a horse’s foot.¹^,² Now, veterinarians know navicular disease is more accurately referred to as podotrochlosis because it involves not only the navicular bone but also a large number of structures that make up the podotrochlear apparatus. Throughout this fact sheet, however, we’ll use the more commonly accepted term, navicular disease, in reference to the condition.