Editor’s Note: This is a short excerpt from Chapter 8 (Musculoskeletal Maintenance) of Understanding Equine Preventive Medicine, written by Bradford G. Bentz, VMD, MS. 

Equine athletes are really no different than human athletes in regard to the effects of aging, exercise, and other use on the joints. Because this is the case, if a horse is used for regular performance, competition, or other exercise activity, one should see changes over a period of time relating to the joints and skeletal system. Indeed, even aging itself can lead to deterioration in such structures. It is, therefore, important that an owner and the trainer understand that no individual horse can or should be expected to compete at the same level throughout its entire life and that gradual progression of degenerative joint disease is normal and expected. However, today we are armed with a number of potentially useful and some highly proven therapies that can be used to prolong both the length of time the horse is able to compete at its highest potential level and the amount of time that the horse is able to perform the particular activity with comfort and success.

There are a number of modes of therapy that can help maintain joint health and reduce pain associated with joint disease. Such therapies may include oral medications, oral joint supplements, intramuscular medications, intravenous medications, and intra-articular medications (medications that are placed directly into the joint). Other therapies include magnetic therapy, acupuncture, topically administered medications, shock-wave therapy, and more.

Intravenously (IV) and Intramuscularly (IM) Administered Joint Therapies

As is the case with oral joint supplements, the availability and use of IV and IM administered joint medications have expanded significantly in the past several years. Such therapies often include hyaluronic acid (HA) preparations (e.g., Legend and others) and polysulfated glycosaminoglycans (PSGAGs) (e.g., Adequan IM). Hyaluronic acid preparations can be administered intravenously as well as directly into the joint. In the joint, HA performs several functions, such as increasing the viscosity of joint fluid, lubricating the joint membrane and joint cartilage, and other potentially significant functions. Administering HA to a joint is believed to increase the viscosity of normal joint fluid and counter inflammation. The effects of HA in a joint are maximized by direct injection; however, there is some evidence that intravenous administration of HA can effectively manage osteoarthritis (degenerative joint disease)