[Tank's Grandma]

I'm sure moondog will speak up, but she recommended "Home-Prepared Dog and Cat Diets, The Healthy Alternative" by Donald Strombeck, DVM, PhD for preparing your own food to control such problems.
I'm going through this problem right now with my cat, and it's been determined he does not have any infection and my vet specifically reccommended Science Diet Light over even the premium food I had for him once he finishes the prescription low pH food. It's what she feeds her own cat. But I'm dealing with a cat, not a dog.
Good luck.