as the carertaker of 3 rescued russians I have seen some bad damage to some shells, but those spots on his/her shell is pretty bad, could be from his previous home could be animal abuse. dog and racoons come to mind. living in california I am able to grow all my food for my torts, I feed mine a wide variety of leaves and flowers. If he is used to veggie mix he may have just decided to eat that and nothing else start mixing in other good turtle food for him so he can get used to it. the foods I use for mine are hibiscus flowers(they do not like the leaves for some reason) grape leaves, radish tops not the vegetable just the tops. dandelions when I can find them lol , artichoke leaves, some nice cactus pieces, and lots lots more. I am currently trying to find a native california foothill lotus that is a wildgrowing weed that desert tortoises like. They are plentiful in san diego so I may go out ther one day and see if I can find some. anyways if you have any questions there ar elots of knowledgeable peopel here who can answer them, BTW I was saddened to ee the poor guys living condition. Did they have a light for him? I did not see one but you never know. anyways kudos for rescuing him and here is to many many good years for him. they are resilient little guys and can bounce back from some pretty harsh conditions.