Equine Diseases - Equine Joint Damage
EQUINE JOINT DAMAGE
Equine Joint Damage can be multi-faceted and wide-ranging. In layman's terms, the equine joint is composed of cartilage which is a tough, elastic, fibrous tissue, other soft tissue and a joint cavity which is filled with synovial fluid. Synovial fluid lubricates joint surfaces, removes waste materials and provides nutrition to the cartilage. Any or all of these can break down and cause equine joint damage.
Most equine joint damage occurs to the horse's legs which are very delicately built. The joints most likely to be damaged are the Knee, Pastern, Fetlock, Coffin and Shoulder joints.
Equine joints are asked to perform demanding tasks. E.g.
Jumping – requiring huge weight on hind joints for take-off and stress for landing on the front leg joints
Sharp Turning – in between jumps, the sharp turns needed for the next line-up stress the hocks
Dressage – requires the horse to move his centre of gravity to the rear, stressing the hind joints, hocks, front pasterns, middle knee joint and fetlocks
Cutting – torque on the rear joints – particularly the hock and stifle joints, when dropping and spinning hindquarters
Roping – sliding and jerking from the calf puts stress on the hock and pastern joints
Barrel Racing – stress on the joints of front and hind limbs
Once the equine joints are stressed, inflammation can set in. If the inflammation becomes excessive or long-term, breakdown of the cartilage is inevitable. This causes extreme discomfort and loss of flexibility and leads the most common forms of equine joint damage which are arthritis and degenerative joint disease.
If not treated, over time the cartilage will erode entirely leaving a bone-on-bone situation which causes grinding and further immobility.
SYMPTOMS OF EQUINE JOINT DAMAGE
- Pain after activity
- Stiffness after inactivity
- Crepitus – a crackling or grating feeling under the skin of the joint
- Decreased performance
- Inability to perform activities that were once performed with ease.
- Appearance of bumps on the extremities.
- Heat - the equine joints are red and feel hot and tender
CAUSES OF EQUINE JOINT DAMAGE
Trauma/Stress to the joints
TREATMENT FOR EQUINE JOINT DAMAGE
Early treatment and careful management will considerably enhance your horse's chances of keeping joint damage under control. The prescribed treatment for your horse will depend on the severity of the damage and the amount and type of work your horse is expected to perform.
Treatment will range across the following spectrum:
Rest – Ensure your horse, particularly a working horse gets enough rest to give the joint damage time to heal
- Exercise Management - Exercise helps reduce pain, prevent further joint damage and can help the horse maintain a healthy weight. Disuse of a sore joint will cause the muscles around it to weaken, resulting in pain.
Diet Management - Weight control is an important part of any equine joint damage treatment. Excess weight puts pressure on the joints.
Glucosamine HCL – improves connective tissue and reduces joint pain
Chondroitin Sulfate – present in high quantities in cartilage but reduced by equine joint damage. Keeping levels topped up could restore cartilage to a normal state. Chondroitin sulfate said to have anti-inflammatory properties and inhibits destructive enzymes associated with cartilage breakdown.
Hyaluronic acid (HA) – decreases damage to cartilage and stimulates production of healthy joint synovial fluid
Ice packs - applied to the damaged area to reduce the inflammation and swelling
Physical therapy - Equine physical therapists are using a number of techniques that range from simple stretching exercises to sophisticated laser equipment.
Controversy surrounds some of these methods
Non-steroidal anti-inflammatory drugs ( NSAIDS) - help reduce the pain and swelling of the joints and decrease stiffness. A low dose reduces pain whilst a higher dose reduces inflammation. NSAIDs do not prevent joint damage and when used long-term, may accelerate joint breakdown.
Analgesics & Anti-inflammatories – these are mainly pain killing and give relief short term
Corticosteroid therapy - injecting corticosteroids into the joint will give immediate temporary relief of the symptoms
Visco-supplementation - the process of injecting a gel-like substance into the joint. This substance lubricates the cartilage and decreases friction thus reducing pain and improving flexibility and mobility. Requires ongoing injections as benefits are only temporary.
Surgery - keyhole surgery (arthroscopy) to the joint. This involves the use of a small telescope inserted into the joint. The procedure allows removal of damaged cartilage, membrane, and bone. It is popular with vets because of the significantly reduced incidence of post operative infection and the reduced need to bandage the limb following the surgery. Procedures such as this have developed significantly in the past decade, particularly for treating the equine shoulder joint.
Gene Therapy - an alternative treatment showing great promise. Instead of having a therapeutic substance injected into the joint, the patient is treated with a gene which will stimulate the production of the required substance in situ. This is achieved by using a vector, such as a virus, to carry the gene into the nucleus of the target cell.