IRAP or Interleukin Receptor Antagonist Protein is an autologous (naturally occurring in the horse) alternative to steroid joint injections that is used to decrease inflammation in a joint.

The principle of IRAP as a therapy utilizes the body’s own immune system.

In times of injury or inflammation, the body produces inflammatory proteins (interleukins) which act as mediators of the inflammatory response. In the injured joint or synovial structure there are receptors for these interleukins. When the two bind, it acts as a catalyst for increased production of inflammatory proteins at the site of injury. Like many other inflammatory processes in the body, the process can become excessive and the inflammation ceases to have a positive function; instead becoming detrimental to the body and to healing processes. This can result in increased level of cartilage and joint damage leading to long term pain and arthritis.

The body also naturally makes a protein to minimize this inflammatory process: IRAP. This protein binds to the same receptor, effectively stopping or reducing the inflammatory cascade caused by interleukin.

When used as a therapy, blood is drawn from your horse into a syringe containing glass beads which cause the red blood cells in the syringe to produce a greater amount of the antagonist protein. The sample is incubated for 18 hours, centrifuged, and packaged into individual syringes. The serum resulting from this process contains a much higher concentration of antagonist protein than normal joint fluid and can be injected directly into your horse’s affected joint(s) or synovial structure(s).


Platelet-Rich Plasma (PRP)
Platelet-Rich Plasma injection is used to treat recent tendon and ligament injuries or those injuries that have not responded to traditional rest and controlled exercise programs. This therapy was adapted for treatment in horses from human medicine in the last 10-15 years. Platelets contain high levels of growth factors that have been shown to enhance access of healthy inflammatory cells to the area of tissue injury and to increase formation of new blood vessels and connective tissue.

Soft tissue injuries treated with PRP have been shown to have a better quality of healing resulting in decreased likelihood of reinjury. Whole blood is pulled from your horse in a special syringe and centrifuged to select the portion containing the most platelets, or “platelet-rich plasma.” This harvesting process takes about 30 minutes and is done stall-side. The injection procedure is done in the standing, sedated horse with a local nerve block. Using ultrasound guidance, the PRP is injected directly into the lesion within the tendon or ligament. The horse is then placed on a strict rehabilitation program and progress is monitored every 60 days with ultrasound. PRP injection is an effective way to increase your horse’s ability to return to his full athletic potential following tendon or ligament injury.