ARTHRITIS: INEVITABLE BUT NOT UNTREATABLE

Good management can head off or lessen the effects of many age-related health issues, but there’s not much you can do to keep a horse from developing arthritis.

“Much like in people, arthritic changes in horses are an inevitable part of aging,” says David Frisbie, DVM, PhD, of Colorado State University.

A horse’s genetics and lifestyle have some influence on how well his joints function as he ages. But there’s no escaping the basic wear and tear that eventually leads the inflammation that normally assists in joint healing and maintenance to outpace the body’s restorative abilities. The result is a destructive cascade of processes that lead to deterioration of the joints: arthritis.

Even if joint problems can’t entirely be prevented, however, there are things you can do to slow the progression of arthritis and alleviate the discomfort it causes. Treatments for horses with arthritis range from feed supplements to intensive, hightech therapies. The best choice for a particular horse depends on many factors, including his age, activity level and the severity of the case. Current therapies include:

• Dietary supplements. A variety of joint support supplements are available. Formulated to aid healing and encourage growth of healthy tissue, many also have antiinflammatory effects. Most contain some combination of substances naturally found in healthy joints, including glucosamine, chondroitin sulfate, polysulfated glycosaminoglycans (PSGAGs) and hyaluronan. Other common ingredients include methylsulfonylmethane (MSM), yucca, avocado-soybean unsaponifiable (ASU) extract and vitamin C.

• NSAIDs. Drugs such as phenylbutazone both relieve pain and interrupt the inflammatory process, which can break the cycle of cartilage degradation. Oral NSAIDs can be administered as pills, powders or pastes, but longterm use can sometimes lead to side effects such as gastric ulcers. Newer products that selectively inhibit only the COX-2 enzymes promise pain relief with fewer side effects. Another option is to apply a topical product over the affected joints.

• Injections. Corticosteroids are potent anti-inflammatory agents that can be injected directly into the joint space to produce immediate pain relief as well as to slow progression of the disease. However, corticosteroids can have side effects, including laminitis, and any injection into the joint poses risks, such as infection. Hyaluronan can be administered either into the joint or intravenously to support joint health. It seems to have an anti-inflammatory effect and to stimulate the body to produce more, better quality synovial fluid. PSGAGs can also be injected into the joint or intramuscularly. These also encourage healing of cartilage and are thought to have an anti-inflammatory effect.

• IRAP (interleukin-1 receptor antagonist protein) therapy. In this procedure, blood is drawn from the horse and treated to stimulate the production of IRAP, which blocks a protein that accelerates joint damage. The serum is then injected back into the same horse’s joint.

• Stem-cell therapy. This cutting-edge treatment harvests undifferentiated cells from the horse’s own body tissues, usually fat or bone marrow, and injects them back into the damaged joint to create new cartilage cells.

Whatever other treatments your veterinarian suggests, she is likely to also recommend exercise, at whatever level your horse can manage. “We know a consistent level of exercise seems to help,” says Frisbie. “This helps keep good muscle strength, which supports the joints and allows less laxity.”