Like many captive elephants, Nidia suffered from chronic foot problems. Fissures had formed in the 55-year-old Asian elephant’s foot pads, and her toenails had cracked and become ingrown. Painful abscesses lingered for months. Nidia had lost her appetite and she was losing weight.Dr. Quetzalli Hernández, the veterinarian in charge of Nidia’s care at a wildlife…