A desert box turtle wandered into my back yard. I live in the middle of a New Mexico city in a neighborhood with small townhouses and small yards. There's really nowhere for him to live around here except in someone's yard and it's luck of the draw with that I suppose. So I've been leaving a water dish out which he soaks in daily. I also feed him bugs, he will come to my back porch when he wants to eat. My big question is about his shell. It's obviously in bad shape. I don't know if this is some sort of infection, or possibly damage from something like a dog (both of my neighbors have dogs). It does look like the back right part of the shell has a puncture that's healing/healed that could be from a dog tooth. Is there anything I can do to help him get his shell healthy? Do you have input on what is wrong with it? I'm worried about the little guy and would like to help if I can. The photo where his head is out further and he looks drier is from the day he showed up. The 2nd photo is roughly about six weeks after showing up. Thanks in advance for your help.