Alternative cat food to prevent bladder stones

Question
Hi,

Over 3 years ago my cat had a stone in her bladder (Calcium Oxilate, sp? not struvite), and my Vet put her on Eukanuba Moderate pH/O.  I've been reading about how cat food could have caused the problem to begin with, and that more natural food would also prevent the problem.  Do you have a recommendation on a natural food?

Thanks,
-Suzanne

Answer
Calcium oxalates form in an acidic urine.  Normal urine is acidic and practically all diets will make the urine acidic for this reason (acidic urine also prevents infection).  Struvite crystals and stones are far more common as they form in an alkaline pH (>7.0).

Low protein diets are recommended to prevent calcium oxalates as well as vegetarian diets, however, you can NOT feed a cat a vegetarian diet.   Feeding canned food is advised as well as limited calcium suppplements, vitamin C supplements, cranberry supplements and excess salt.

I am not aware of any non-prescription diets that will get the pH of the urine to be 7.5 ... Royal Canin (formerly Waltham) S/O would probably be the most natural prescription diet available.

Adding supplements such as potassium citrate and Vitamin B6 may be of use.