HELP!!! I have a box turtle that I have had for three years. I took him to the vet a few months ago and she told me my best bet was to let him go. I can't do that because he's my baby. Tonight I noticed that on his belly his shell looks like brownish tree bark on the sides. Also, a distinctive indention in the middle. What can I do to make him better? What is this? ANSWER ME ASAP! thanks.