Navicular disease is a degenerative disease that affects the horse’s heel. The disease has long been thought to be caused by the degeneration of the navicular bone. This degeneration can involve damage and inflammation to surrounding structures such as:
- The deep digital flexor tendon (DDFT)
- Impair and navicular suspensory ligaments
- Navicular bursa
Symptoms of Navicular Disease
Today, not all horses suffering from navicular disease show changes in the navicular bone, but surrounding structures may be inflamed or damaged. Each cause heel pain and lameness in horses. While not solely synonymous with navicular disease, symptoms include:
- Lameness in one or both front feet
- Horse walks toe-to-heel instead of heel-to-toe
- Shifting of weight from one front foot to the other
- Horse no longer wants to move out
Diagnosis and Treatment of Navicular Disease
Diagnosis:
- Painful response to hoof testers across the heel
- A (temporary) nerve block that numbs the heel eliminates the lameness
- Radiographs reveal degenerative changes to the navicular bone
- In a small percentage of cases, a MRI will aid in diagnosis
Treatment:
- Correct shoeing to improve the angle of the foot
- Injections to either the coffin joint or the navicular bursa
- Finally, a neurectomy can be a viable treatment option if the previous treatments are ineffective
Neurectomy for Navicular Pain Relief
A neurectomy, also known as “nerving,” can be an option to alleviate the pain associated with navicular disease when other treatment options such as shoeing changes and injections no longer control pain. The surgery involves removing both the lateral and medial palmar digital nerves on the back of the pastern. As a result, the horse loses the feeling in its foot.
After surgery, a horse can go back to work in about four weeks. Show horses whose careers were once thought to be over due to navicular syndrome are successfully competing in the show ring. Dr. Rich Hartman stated he has had horses “go back to barrel racing, jumping and pleasure.‚Äù
A neurectomy is generally used as a last resort method. It does not correct navicular syndrome—it only removes the pain associated with the disease. Dr. Hartman warns clients that surgery is “not a permanent fix: Horses can expect 1-4 years of pain management.” The nerves tend to grow back, although not along the same path, and the pain can eventually return.
After Neurectomy Care
After a neurectomy, you need to pay special attention to the horse’s feet. The foot is numb, making them prone to injury. Dr. Hartman cautions, ‚ÄúIt is critical to check a nerved horse’s feet daily. These horses have no sensation in their hoof and they are at greater risk of abscess, and puncture wounds.” Other uncommon complications include the breakdown of the deep digital flexor tendon (DDF) or the formation of painful neuromas.
If you‚Äôre looking to improve your horse’s quality of life, or continue on with their show career a neurectomy can be a good option when pain can no longer be controlled with other therapies such as:
- Corrective shoeing
- Anti-inflammatory medications
- Joint injections