Arthritis Treatment Options - Choose the right help for your horse
Tom Lenz, D.V.M.
Several treatments are available if your horse has arthritis. (See Spring 1997 issue). What you do depends on the stage and severity of the damage. There are treatments aimed at relieving soft tissue inflammation and pain, restoring normal joint fluid and preventing or slowing down cartilage degeneration. A combination of therapies can often provide the best results.
There are several options in the early stages of arthritis (before cartilage damage occurs). Rest, physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), sodium hyaluronate (HA) or polysulfated glycoaminoglycans (PSGAG) injected either in the muscle or directly into the joint, and corticosteroids injected into the joint, might be used.
Which option is best? It varies from horse to horse, but here are some of the factors you can consider as you consult with your veterinarian.
Rest: Though not always a popular option with racing and show horses, rest is always advisable, and may involve a few days up to several months.
Physical therapy: This includes treatments such as cold hydrotherapy (ice), heat therapy (sweats), as well as corrective shoeing and massage. While helpful, physical therapy alone is often inadequate.
NSAIDs: These are part of a family of compounds useful in reducing inflammation, pain and fever. They are the most commonly used group of drugs for joint or soft tissue lameness in horses. The most widely used NSAIDs in equine medicine are phenylbutazone (bute), Banamine and aspirin. NSAIDs are used in both acute synovitis and chronic degenerative joint disease (DJD).
These drugs have no effect on the destructive enzymes already present in the damaged joint, however. When used alone, NSAIDs can actually lead to destruction of the joint, because they reduce pain and encourage the horse to resume using the injured leg despite the presence of joint disease. NSAIDs are best used in conjunction with other treatments such as HA or PSGAG.
Corticosteroids: These are different from the anabolic steroids that are often associated with abuse. Corticosteroids are the most potent anti-inflammatory agents available and are used by many veterinarians in both early and advanced stages of arthritis. They are usually injected directly into the joint.
The subsequent reduction of joint inflammation quickly diminishes pain, swelling and heat, as well as suppressing harmful enzymes and free radicals. Corticosteroids may be used alone but are more often used in combination with HA or PSGAG.
Cartilage-protecting compounds: Hyaluronic acid (HA) and polysulfated glycoaminogly (PSGAG) can perform a variety of functions which ultimately result in improved joint and cartilage health. As discussed in the Spring 1997 The Mane Points article, HA lubricates soft tissue in a normal joint, and forms a barrier against invasion of foreign material.
HA, either injected directly into the joint (or given intravenously), inhibits the release of damaging enzymes and free radicals into the joint; reduces inflammation; aids in returning the joint fluid to its normal consistency; protects the cartilage; lubricates soft tissue structures within the joint; and stimulates the lining cells of the joint (synoviocytes) to produce more healthy HA.
Clinical studies have determined that intravenous administration of HA is as effective as direct injection into the joint. Also, intravenous injection has the potential to treat several joints when more than one may be involved, or in cases where lameness is present but the specific joint is not yet identified.
PSGAG is similar to compounds in the horse's joint cartilage and has been shown to suppress inflammation; provide relief from heat, swelling and pain; stimulate production of HA; improve joint lubrication; and stimulate cartilage healing. The product can be injected directly into the joint or in the muscle.
Glucosamine and chondroitin sulfate: Veterinarians have mixed opinions as to the effectiveness of these two drugs.
Studies in Europe concluded that orally administered glucosamine caused a reduction in clinical joint pain, tenderness and swelling. It is thought to stimulate the formation of synovial fluid and enhance the repair and regeneration of cartilage.
Tom Lenz, D.V.M., is director of animal health with Bayer.