I found this forum when searching for opinions about RC Urinary SO. My male cat was put on it (dry version) about six weeks ago when he had a UTI. They found tons of crystals in his urine so he's supposed to be on it for life. He's handling it okay, but my female cat was also eating it and it caused her to get constipated and act rather dehydrated. I didn't know what was causing it at first (she also just went on methimazole for hyper-t) but a couple days ago I switched her back to the food she was on before and there was an almost immediate difference. I think I'm going to have to feed them separately since I'm afraid to take my male cat off it and he's reacting a little better (he has somewhat dry stools too but nothing like my other cat). I think the high sodium content is the contributing factor, and I hope the dehydration it causes isn't dangerous. I'd be curious if anybody else has had a similar experience on this food. I'd give them the canned version but they HATE it!