Arthritis
Osteoarthritis is a degenerative joint disease that causes lameness in affected horses. Osteoarthritis begins when the synovial fluid that lubricates healthy joints begins to thin. The resulting decrease in lubrication causes the cushion of cartilage to break down.
As the cartilage breaks down, the horse's body attempts to repair the damage by replacing it with new bone (bone is produced much faster than cartilage, due to its abundant blood supply). The ends of the bones in the joint thicken and the new bone may form bone spurs that grind together causing considerable pain.
Osteoarthritis primarily affects weight-bearing joints in horses such as the:
- Hocks (ankles) where it is commonly referred to as Bone Spavins - common
- Fetlocks - common
- Pastern joints and Coffin joints where it is referred to as Ringbone when more severe - common
- Stifle (knee) joints - less common
- Spine (neck and back) - less common
Osteoarthritis does not usually affect other equine joints, except where previous injury has occurred or areas where there has been repetitive or abnormal stress.
When a horse reaches the age of 15 or thereabouts, the cartilage begins to break down faster than it is produced. The tendons and ligaments also tend to stretch as a horse ages, resulting in tears, joint instability and inflammation.
Another contributory factor is abnormal growth such as hooves that turn out or bowed legs. This may cause the cartilage to wear unevenly. Horses that are overworked or not physically fit are also more likely to suffer from the condition.
You should suspect arthritis if your horse exhibits any of the following symptoms:
- Pain, stiffness and swelling around a joint that lasts longer than two weeks.
- Early in the disease, your horse's joints may ache after activity. Watch closely for signs that your horse may be experiencing some discomfort.
- Stiffness that tends to follow periods of inactivity, such as sleep or prolonged standing.
- Grating sound ("crepitus") when the joint is used.
- Decreased performance and inability to perform activities that were once performed with ease.
- Appearance of bumps or swellings, especially on the extremities.
If your horse's joints are red or feel hot or tender, he/she may be suffering from something other than osteoarthritis. Check with your vet about other causes of those symptoms, such as autoimmune or septic arthritis.
Once your horse has been diagnosed with osteoarthritis, you and the vet can determine a course of treatment. The chosen treatment will depend on the severity of the disease and the amount of work your horse is expected to perform. On occasion,box rest and use of ice packs may be all that is needed to reduce inflammation and swelling. Treatment for established arthritis normally includes analgesic (pain-killing) and anti-inflammatory medications, exercise management and, occasionally, surgery. |
