Brief Description
Navicular disease generally refers to progressive degeneration of the navicular bone, the small bone in the hoof that lies behind the coffin bone or third phalanx. Navicular syndrome is used to describe any condition causing pain in the area of the navicular bone or the heel, including the navicular bursa, deep digital flexor tendon, coffin joint, or any of several ligaments.
Possible Diagnostic Tests
It is usually not difficult to localize lameness in the horse’s heel with an examination that includes applying a hoof tester, flexing the lower limb, standing the horse on wedges, and blocking local nerves. However, determining exactly what structure within the hoof is causing the pain can be a challenge. X-rays have always been the basis of a navicular diagnosis, but newer methods such as x-rays with contrast dye, ultrasound bone scan (nuclear scintigraphy) and especially MRI appear to be better at identifying which specific structures are involved.
Prescription Medications Available
If a specific structure within the hoof can be identified as diseased or injured, anti-inflammatories such as corticosteroids or Hylauronic Acid (Legend®) may be injected directly into the area. Prescription non-steroidal anti-inflammatories (NSAIDs) such as bute (phenylbutazone) and Banamine® (flunixin meglumine) are commonly used to relieve pain. The human drug isoxsuprine, a vasodilator which increases blood flow, is often prescribed because one theory suggests the disease is caused by lack of blood flow to the bone.
Supplements that May Lend Support
It may be helpful to provide an oral joint supplement with active ingredients similar to Legend ®and Adequan® (i.e. Glucosamine, Chondroitin Sulfate and Hylauronic Acid). Because fighting inflammation is key to keeping the horse comfortable and supporting stressed tissues, natural anti-inflammatories such as MSM, Omega 3 Fatty Acids, and certain herbs like Boswellia, Yucca and Bromelain may be beneficial. Studies support the use of nitric oxide, the body’s own vasodilator, in other hoof conditions. Therefore supplying its precursors (arginine and citrulline) or ingredients known to protect the cells that line blood vessels (niacinamide and N-acetyl cysteine) may also provide support.
Other Management Suggestions
Corrective shoeing is a large component of the overall treatment plan for horses with navicular. Mild exercise is preferred over stall rest. Extracorporeal shock wave therapy and desmotomy (cutting) of local ligaments are being explored as treatments. Cutting the nerves to the foot (palmar digital neurectomy) remains a last resort.
Questions to Ask Your Veterinarian
- Why did my horse develop navicular?
- How much longer will I be able to compete him?
- If he has the neurectomy, will he still be able to feel his foot and be safe to ride?
For more information on this topic or general horse care information, contact a SmartPak Product Specialist at 1-800-461-8898 or visit the website at www.SmartPakEquine.com
Article provided by SmartPak.
Dr. Lydia Gray is the Medical Director/Staff Veterinarian for SmartPak, where she guides research and new product development, answers questions on her Ask the Vet blog, and speaks around the country at various events such as Equine Affaire, Dressage at Devon, and the USHJA Trainers’ Symposiums. |
