Scout is on Purina U/R for her kidney stones, bladder stones and crystals. I also started Decker on it last week when he started peeing blood and the vet said to continue him on it. Since Scout has only been on it for about 6 weeks I can't say a lot about it but she is feeling much better, more playful (and bossy) and she and Decker love the taste. Of course all the other cats do too so it's a challenge to keep them out of it.