urinary tract diet

Question
My 2 year old male cat was diagnosed with urinary tract infection a few years ago, since then I have been feeding him Royal Canin Urinary SO. Does my cat need to eat this special prescription food available only through my vet, forever or is it safe to feed him a good quality cat food from the pet store with low ash? (I am a student with 4 cats on a budget, all my cats eat the Royal Canin Urinary SO and it is very expensive!)

Answer
I don't really study Royal canin products..and you said ALL of your cats are on the RX diet? You could ask your vet if it is really necessary to continue this
unless you have all male cats as they are prone to UTIs
If you do get the OK to switch to OTC food..I like Purina One and I believe they have a formula for maintaining urinary tract health
Umm.. also ask the vet the prices of Science Diet RX diets and also Purina RX diets I would hope they would be less pricey than Royal canin and just as reputable