I can't comment on them in captivity, but my father-in-law found an injured one near his rice field last fall. While I was cleaning it up, it had a funk that would put a musk to shame--don't know if it was musk, the smell of the mud on it, or the wounds (which looked pretty fresh and relatively clean). On a happier note, the turtles wounds looked worse than they really were, and he escaped during the night before I could do any more for him. Probably back to my in-laws' paddy.