Also known as caudal heel syndrome, it is a disease in horses that causes them foot pain and lameness. Classical treatments of the species usually do not offer satisfactory results leaving most horses lame and requiring to be occasionally euthanized. Navicular disease has been suggested to be arthritic in nature with other possible causes including inflammation, adhesions between the deep digital flexor tendon and the navicular bursar and high-pressure inside the navicular bone. The disease is diagnosed based on radiographic and clinical signs i.e. a veterinary officer bases his/her diagnosis on what they see during physical examination and also by checking x-ray images of the horse’s hoof area. X-ray images help support a diagnosis of this disease while also rolling out other causes of lameness in the horse.
Horses with navicular disease usually exhibits certain tell-tale signs. For instance, a horse may have a history of lameness in a front leg. The lameness is usually gradual and can also be present in both front feet. However, one leg may usually be worse than the other. The horse may also have a choppy uncomfortable gait or a history of stumbling. Even though any horse can develop this disease, the two breeds most commonly affected are thoroughbreds and quarter horses with the reason for their predisposition to the disease being that they are both very large horses that rest on relatively small feet. The onset of clinical signs can begin at any age however, the highest period of occurrences between the ages of 7 and 14.
Even though the disease does not go away with relative ease, it can be treated through proper management. Therefore, most horses affected with the disease can be treated and returned to their previous condition. The foundation for treating horses with signs of the disease is proper shoeing. This implies the essential practices of balancing a horse’s hooves side to side and front to back. The pastern should be parallel to the back of the hoof, while the line of the pastern should be parallel to the front of the hoof. A very common problem seen in horses suspected to have navicular disease is underrun heels and long toes. This problem can be corrected by trimming the long tour until the front of the hoof becomes parallel to the line of the pastern.
Another aspect of treatment is via drug therapy. As of now, the most successful drug therapies involve using Isoxsuprine and oral gallium nitrate. The drugs help restore soundness by dilating blood vessels, which presumably increases blood circulation to the navicular bone. According to studies, approximately 80% of horses treated with the mentioned drugs positively respond to it. The duration of the response however varies from horse to horse therefore, repeated courses of treatment may be required as seen necessary.
The last and perhaps least conventional method of treatment is through exercise. Since issues related to navicular disease entail reduced blood circulation and trauma to the navicular bone, circulation to the foot can be increased through exercise. Via structured riding for 30-60 minutes six times per week, horses can gradually learn to bear more weight on their hind legs. By working the horse at a trot, they become more proficient at bearing the weight from the front, painful legs to the hind legs.