Tildren is a drug used for the treatment bone disease. Bone is constantly being renewed throughout the entire skeleton regardless of the horse's age. This continuous remodeling is a normal process  that allows the horse's bones to adapt to the demands associated with different athletic activities. Bone goes through a cycle of resorption and reformation as a part of this process. This remodeling process is significantly altered in disease processes involving the bone, such as arthritis and navicular disease. There is excessive resorption of bone, resulting in pain and lameness. Tildren inhibits bone resorption and stimulates bone formation, resulting in greater bone density. Tildren is given via regional limb perfusion and/or slow intravenous infusion. Improvement is typically seen within 1 month after treatment.