As most horse owners are well aware, degenerative joint disease, or osteoarthritis, and its associated forms of lameness can affect any horse, from the back yard pet to the highest level performance horse. Fortunately, a number of research studies have been performed demonstrating the benefit of oral and injectable joint supplements in treating and preventing joint damage in the horse. These supplements are reported to decrease inflammation and provide building blocks for synthesis and repair of fluid and cartilage in the joint.
The most common and most effective oral supplements contain glucosamine, chondroitin sulfate, methylsufonylmethane (MSM), hyaluronic acid, and avocado/soybean unsaponifiable extracts (ASU). Glucosamine and chondroitin sulfate are the backbones of most supplement programs. In combination they are shown to relieve pain, slow cartilage breakdown, encourage healing, and prevent further damage in the joint. The severity of injuries is also said to be lessened when therapeutic levels are present in the horse at the time of the injury.
Unlike oral joint supplements, injectable products are controlled by the Food and Drug Administration and must be administered under supervision of a licensed veterinarian. The only two products commercially available in this class are hyaluronic acid (HA) and polysulfated glycosaminoglycans (PSGAGs). Hyaluronic acid has been demonstrated to decrease inflammation and prevent further degeneration of the joint by working on the cartilage and joint fluid itself. It has been very effective in older horses, and positive results may be seen as quickly as a few days. HA can be given intravenously (Legend®) or into the joint itself by your veterinarian. PSGAGs function to inhibit degradative enzymes and to stimulate the lining of a diseased joint to produce healthy viscous joint fluid. They are intended for intravenous (Polyglycan) or intramuscular (Adequan®) administration. The intramuscular form has proven to be most effective and can be given as often as every five days to once a month.
There are hundreds of different products on the market claiming to be effective in treating and preventing equine joint disease. It is important to read these labels to make sure the product contains the appropriate ingredients and at therapeutic levels. It is also important to understand that individual horses with similar conditions may respond differently to the same products and doses.
Daily Minimum Therapeutic Levels – Most Effective
Glucosamine: 6,000 to 10,000 mg (10,000 mg recommended in working horses)
Chondroitin Sulfate: 1,250 to 5,000 mg
MSM: 15,000 to 20,000 mg for horse with an ongoing problem; 10,000 mg for small horses
Hyaluronic Acid Oral: 100 mg