Desert tortoise

Question
My desert tortiose Sid was a rescure from someone who didn't want him anymore. I have had him for several years and he hangs out in the backyard and occasionally he runs around in the house. For his winter nap I bring him inside.  He shares the backyard with a dog and two cats. The cats ignore him and the dog gives him kisses.  The dog eats out of the same veggie pile as Sid. His stool has been runny for most of the summer and now it is firming up.  Last summer he hurt his left front foot.  I took him to the vet and X-rays showed nothing broken.  This summer his foot is fine.  Now he has developed some hard white spots on his skin, legs and neck.    He gets feed veggies once a day although he would like more.  He seems fine he eats good and moves around with no problems.   The weather is getting cooler so he is slowing down a bit and starting to sleep a little more.   Thanks for you time.  

Tandy.

Answer
You've not been very specific, but my instructions require that you be, and that's regardless of whether this is an indoor or outdoor housed animal. What exactly does his diet consist of, in what proportions and frequency? Supplements and when and how much? CA. is a big state, so what part of CA do you reside and what is the habitat like, and the average temperatures and humidity? Does he have shaded hides or burrows or not? A dedicated water source he uses ad libitum, or do you soak him yourself? Couldn't you have attached some photos of these spots? You're asking a health question. If you want answers, please provide a specific husbandry background AND photos.