Neely Heidorn | 2/19/2011 1:35:04 AM
Sara Bercier, School of Veterinary Medicine, LSU, Class of 2013
Daniel J. Burba, Professor of Equine Surgery, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, LSU
Neely L. Heidorn, Assistant Professor of Animal Science, Department of Animal Sciences, LSU AgCenter
Degenerative Joint Disease (DJD) of the hocks, also known as Bone Spavin, is a common condition in the equine athlete that causes lameness. Arising from varying factors, bone spavin is ultimately the result of destruction of the joint cartilage in the bottom two joints of the hock.
When wear and tear of a joint occurs, physical and biochemical damage is inflicted upon the articular cartilage. Enzymes and other agents from the joint lining (biochemical agents) are released inside the joint and destroy the components of the cartilage, triggering tissue inflammation which, in turn, causes pain, effusion, and reduced range of motion. As the cartilage in the joint erodes due to this cyclic insult to the joint, the bones of the joint begin to grind against each other, resulting in further disability and pain.
Generally, the condition begins with joint insult and ends with severely damaged cartilage, damaged bone, inflammation to the synovial membrane and joint capsule, bony projections (spurs) around the joint, loss of joint integrity, fusion of the opposing bones, and resulting rigidity or loss of the joints.
Clinical signs will vary according to the severity of the disease, but bone spavin may be considered if a horse presents with the following:
A thorough lameness exam, coupled with the horse’s history, will aid in making a diagnosis, but ultimately, radiographs of the affected joints can confirm bone spavin.
Important Points in Treatment/Management:
Once a diagnosis of bone spavin is confirmed, the proper course of treatment can be determined. The severity of the disease and the anticipated future use of the horse will influence the type of treatment.
Occasionally, restriction, adequate rest, and the use of ice packs (ie. Game-Ready®) may be all that is necessary to reduce acute mild inflammation and swelling. For more severe, established cases of bone spavin, analgesics (pain killers), anti-inflammatory medications, exercise management, and, sometimes, surgery may be required.
Typically, analgesics and anti-inflammatory medications alleviate pain, not improving the condition, itself, or preventing further damage, and should, therefore, only be used in addition to lifestyle modifications including, but not limited to, dietary management, adequate rest, proper shoeing, as well as careful exercise management to reduce joint damage from overuse. This is particularly important in young athletes.
Oral and injectable medications are available for treatment. Intra-articular (joint) injections, such as corticosteroids, ultimately are the best approach to treatment for chronic cases. Intra-articular corticosteroids provide relief by reducing inflammation within and around the joint, reducing pain and providing greater mobility.
Continuous relief requires additional injections. Surgery (joint fusion or welding) may be beneficial in alleviating pain and increasing soundness for severe chronic cases.
In a majority of cases, prognosis is good, especially for less severe cases, with treatment.
A horse’s risk of developing bone spavin increases with age, conformation anomalies (cow hocked or sickle hocked), performance demand/workload, and genetic predispositions towards defective joint or cartilage physiology. For these horses, a single traumatic incident can result in bone spavin. However, even previously sound horses can be afflicted with bone spavin after years of stress to the joints. Heavier breeds and obese horses may be more prone to the condition due to joint stress from the excess weight. Repeated injury and stress on the joints can further damage the cartilage, and improper shoeing and continual exposure to areas with poor footing may also exacerbate the condition.
Prevention or reduction of the onset of severely debilitating bone spavin is dependent on good management and early detection.
Estimated cost of treatment: varies depending on severity of disease
If you would like to consult a veterinarian about degenerative joint disease please contact:
Equine Health Studies Program
School of Veterinary Medicine
Louisiana State University
Baton Rouge, LA 70803