Arthritis is inflammation of a joint causing pain and stiffness. The word arthritis is often used to explain a range of conditions including degenerative joint disease, osteoarthritis and synovitis.
How does it occur?
Arthritis often develops following interference with normal joint structure and function of a joint such as damage to the smooth protective cartilage covering the end of each bone or even the bone itself. Damage can occur by:
- Damage to joint capsule and ligaments
- Age related wear and tear
In response to damage to the surface of the joint, new bone is formed which is rough and not covered by cartilage. This results in reduced joint movement and pain.
Speed of onset
Arthritis can happen very quickly in the case of traumatic injury or infection to the joint when symptoms of pain (lameness) develop very quickly or it can develop gradually over a longer period of time when associated with age related wear and tear to the joint.
- Visible swelling of joint – Joint inflammation results in more joint fluid being produced
- Restricted range of joint motion
- Pain on flexion of the joint
The symptoms exhibited vary according to the cause of arthritis and joint involved. Not all symptoms will be present in all horses.
Arthritis can be diagnosed through thorough clinical examination looking for swellings, reduced range of movement of limbs and pain on flexion in addition to examining for lameness.
In many cases additional examinations will be required including:
Nerve Blocks – injecting local anesthetic around specific nerves to remove pain from specific parts of the leg.
Radiography (xrays) – to assess bones at the joint surfaces. This is particularly helpful in long term arthritis and will not identify early cartilage damage. (NOTE: A horse can have arthritic changes visible on radiographs but may still move comfortably and compete successfully).
Joint Fluid collection – for laboratory analysis to look for signs of infection.
Nuclear scintigraphy (bone scan)
Treatment is determined by the cause of arthritis and may involve:
- Flushing the joint with sterile saline and use of antibiotics when the joint in infected
- Use of oral non-steroidal anti-inflammatory drugs such as suxibutazone, phenylbutazone and meclofenamic acid which reduce pain and inflammation.
- Use of injectable products such as polyglycosaminoglycans and hyaluronic acid
- Medication of the joint itself with corticosteroids and hyaluronic acid to reduce inflammation and improve lubrication.
- Arthroscopy – surgical intervention may be helpful in some cases
In acute cases (eg septic joint) and if appropriate and timely treatment is undertaken, complete cure may occur.
In longer term arthritis (eg age related wear and tear) ongoing treatment may be required.