So I have a cat that almost died from urinary blockage and the same food was prescribed to him... it helped, but it's not nutritious and it's expensive. I did a lot of research and all sources seem to agree that it's an the dry food itself that's causing the stones due to the magnesium and ash content and the dehydrating quality of dry food. Cats already don't drink a lot of water, dry food dehydrates further. A solution that worked for me was simply switching to wet food. I don't even get very expensive wet food, I'm using Sheba brand currently. We've been 2 years without incident, after 9 years or him having UTIs and FLUTD at least once a year. The last time he got sick, my vet warned that he would need to have his urethra widened to prevent it happen again. Haven't needed to do that. Also, a water fountain for a drinking dish, and add some water to the canned food.