[107barney]

If you want nutrition advice, I suggest you contact a vet nutritionist. And when you do, if you contact the one some of us use, she'll tell you to get a culture done.

BTW most grains are acidic. Therefore the ph # would go down, not up if the urine became more acidic. So your vet was correct.

Struvites can't form in normal to acidic urine. The best way to do this as I said is to liquify the diet with water, broth, etc. After you've done a culture.

So to recap:
low pH = acid
high pH = alkaline
grains = acidic
acid/low pH = struvites can't form but oxalate crystals can
struvites form in alkaline urine, usually due to infection
Culture is needed.