Joint injections are a common form of treatment used in our equine athletes. But what exactly is your veterinarian doing when he or she performs a joint injection? And what are the benefits and side effects of this treatment?

Joint injections are generally used to treat inflammation of the joint or arthritis. Arthritis is the body’s way of trying to protect a joint that is damaged. This damage can be the result of wear and tear, a sudden traumatic event, or poorly conformed or built limbs. The most common form of arthritis is the wear and tear variety. This is the type of arthritis seen in young equine and human athletes, as well as geriatric patients of all species. This problem is the result of wear and tear on the cartilage causing inflammation and irritation in the joint. Cartilage is the soft tissue that allows two bones in a joint to glide smoothly across each other when the joint is flexed. Similar to the way the Teflon coating on a frying pan lets things slide around the pan with less friction. If the Teflon on the pan wears thin or gets scratched, things don’t slide as easily. Likewise, if the cartilage in a joint wears thin or gets torn, the joint does not flex as smoothly and inflammation occurs with every movement. If your horse is an athlete or started working at an early age, he or she is more likely to have this wear and tear. Just like Emeril’s frying pan is going to wear out much sooner than those of us whose idea of cooking is warming take out in the microwave.

So how exactly do joint injections treat arthritis? The main type of drugs that are used are corticosteroids or cortisone-like drugs. These medications are very strong anti-inflammatories. In arthritic joints they improve the conditions in the joint by reducing the chemical reaction associated with inflammation. The inflammatory reaction has number of effects including releasing chemicals that cause further damage to the cartilage. By stopping these harmful chemical reactions, low doses of corticosteroids actually have a cartilage protecting effect in an arthritic joint. Stopping this chemical reaction is also important because it stops the pain inflammation causes. So by reducing the harmful side effects of inflammation, we decrease the pain and progression of arthritis.

Despite the overwhelming benefits of these drugs, they must be used properly to avoid side effects. There is a common misconception that the use of cortisone is extremely harmful to cartilage. This idea comes from early findings that discovered that using corticosteroids in healthy, non-inflamed joints degraded the cartilage. Fortunately, later research showed in inflamed joints, these drugs actually decrease degradation of the cartilage. In addition, it was realized that using lower doses at less frequent intervals decreased negative side effects. Thus the benefits of these drugs are gained, while minimizing the side effects. In addition, the discovery over the last few years that combining hyaluronic acid drugs, such as Legend or HyVisc, with a corticosteroid further reduces any negative side effects and adds a number of cartilage protective benefits.

Equine arthritis is a disease that is intensively being researched. Because of this our knowledge and treatments are constantly changing. Joint injections, however, remain a large part of our treatment regime. As a result, having a good understanding of this treatment option is important. In this way you will be better able to understand your veterinarian’s attempts to help your horse move and feel better.