Zycosan is indicated for the control of clinical signs associated with osteoarthritis in horses. Zycosan contains 250 mg/ml pentosan polysulfate sodium. Osteoarthritis is the leading cause of lameness in horses. Most horses will experience lameness at some point in their lives. OA can occur in any joint in the horse’s body, including the carpus, hocks, fetlocks, stifles, and other weight bearing joints, as well as the neck and back. It can significantly impact a horse’s overall health and athletic ability. Horse arthritis medicine can help. For intramuscular use in horses only. Zycosan does not contain a preservative. Discard unused vial contents. Pentosan polysulfate sodium. This is a prescription item requiring a VCPR.