My cat who is just about 1 year old was put on Hill's Science Diet C/D due to crystals in his urine. I've had him on this for a few weeks and he does seem like he has improved and is going more freely. However, looking at the ingredients in this diet, it almost seems like junk-food store brand cat food. With things like Chicken by-product meal and Corn gluten meal, how is this "good" cat food? Is there a better alternative that won't block up my kitty? Also... Should I only be feeding wet food instead of dry?