If you visit Smithsonian’s National Zoo in Washington DC, you may notice on of zoo’s resident elephants, Shanthi, strolling around in stylish Teva boots. While the footwear makes the 9,000-pound pachyderm stand out among her peers, its primary purpose is to provide the 41-year-old relief from the side effects of arthritis, a chronic condition that causes painful inflammation and stiffness of joints.