FInd out what kind of crystals he has; my Samuda had crystals and was prescribed C/D but as we are a large family, I didn't want to have to feed it to my non-UTI cats, nor did I want him to have to eat this unpalatable-looking food exclusively for life; I discussed it with his vet, who prescribed an alternative: METHIGEL. This is a methionine gel supplement -- it is also available in tablet form -- that is supposed to balance the urine Ph and prevent crystals from forming. Check with your vet about this for your little guy -- see if it is appropriate for him, because if it is, you can then feed all of your cats including him a quality premium food (there are many of these, and it depends on your budget and preference as to which one(s) you feed. Personally, I feed Nutro Max Cat, Nutro Natural, Natural Balance, Optimum Nature's Recipe, Triumph, ProPlan, Solid Gold Katz-n-Flocken, PetGold, and Trader Joe's, the latter being a high-end supermarket chain which makes its own cat food brand. Other TCS members have their preferences, so you may want to get more opinions than just mine. But I would definitely discuss Methigel with your doctor!