My dog had a kidney stone removed and was put on Science Diet C/D. She did very poorly on this food and she gained a lot of weight on it, bad skin and coat. My Vet agreed but said to choose another food but they did not carry anything else. Acn anyone advise me of a dry food that would be good for my dog that was low in magnesium and would support her problem with the kidney stone? she does not have stones now.