Navicular disease in horses is a common diagnosis for lameness in the front foot. The label navicular disease is used to describe a variety of conditions, including a progressive degenerative condition involving the navicular bone (which is located behind the pedal bone inside the hoof capsule), the bursa (the joint capsule that sits around the bone) and the deep digital flexor tendon (which runs over the navicular bone before attaching to the pedal bone), of one or, more commonly, both front feet.
Navicular is not a single ‘disease’ – it is a syndrome of abnormalities. Although the term – along with ‘navicular syndrome’ or ‘palmar foot pain’ as it is sometimes known – was once widely used as a generic diagnosis of heel pain, thanks to advances in technology, vets now use the term ‘navicular disease’ to specifically refer to changes within the navicular bone structure itself, identified by MRI scanning.
Signs of navicular disease
Navicular disease typically affects both front feet, although one foot is often worse than the other, so your horse may initially appear lame on one front leg. However, on the lunge the horse may show lameness on the inside leg in both directions.