Jen,

Hill's makes a diet for Oxylate crystals: http://www.hillspet.com/zSkin_2/prod...=1108073609468

Feline X/D comes in wet and dry. If your vet offers Hill's, they can get X/D. (I used to do the food ordering at the vet, its VERY easy to order a different/new food.)

Poor you, poor Rutherford. This has to be frustrating and wareing on you.

Gentle hugs to you both.