Osteoarthritis is also known as degenerative joint disease (DJD) and is one of the main causes of lameness in horses. Osteoarthritis occurs when the cartilage surrounding the joints is destroyed, which produces pain and inflammation. Areas that are affected the most are knee, hock, fetlock and coffin joints. Usually, therapy involves intra-articular medications such as hyaluronic acid and/or steroids, rest, NSAIDS (bute or banamine), shockwave therapy, polysulfated glycosaminoglycan (PSGAG) such as Adequan, intravenous hyaluronic acid (Legend), and oral supplements (for example GLC5500) that contain glucosamine and/or chondrotin sulfate.

   Treatment with Interleukin-1 Receptor Antagonist Protein (IRAP) utilizes progressive gene therapy to combat osteoarthritis in your horse. Interleukin-1 (IL-1) is a type of cytokine and is secreted by many types of cells. A cytokine is a chemical secreted by the cells of the immune system to attack infections and apoptotic (damaged or dying) cells. IL-1 is an important part of the inflammatory response but in the case of your horse’s joints, sometimes can be detrimental. The joint fluid carries a protein called interleukin-1, which plays an important role in inflammation and accelerates the deterioration of tissues like joint cartilage. Interleukin-1 Receptor Antagonist Protein (IRAP) blocks IL-1 from binding to tissues and inhibits the damaging consequences of IL-1.

   The procedure begins with drawing blood from the horse that will be treated with IRAP into a syringe. The syringe is specially prepared with glass beads that stimulate production of the antagonist protein and an anticoagulant. The blood is harvested, incubated and centrifuged to separate the plasma (abundant with IRAP) from the blood. Typically, IRAP treatments are once a week for three weeks and usually, after that time, the horse can return to normal work.

   IRAP is another therapy to be added to the battery of weapons that the equine veterinarian has to combat osteoarthritis in your horse. The reason IRAP is so exciting is its’ potential for a long-term effect on battling osteoarthritis. Whereas some of the therapies listed above might only have short-term effect, IRAP has the potential to stop the cartilage matrix from being degraded and increase healing. IRAP has the ability to stop the inflammation cycle and bring comfort to your horse. The research on IRAP is ongoing but the results have been very encouraging. Please call us at The Equine Center if you think that your horse is a candidate for IRAP or have any more questions.