Found this PH information on another site. You will notice the recommendation by vets concerning pH.

This is where I found the information. Please note this is excerpted information below and the full article is available at:
http://cats.about.com/cs/catmanageme...rinaryhlth.htm

"A great deal of research has been on-going as to the relationship of diet to urinary tract health, and the thinking has changed over a period of just a few years. Originally it was thought that diets high in magnesium and ash contributed to the problem; now more emphasis is being placed on the pH of urine (acidic or alkaline). (Veterinarians recommend a range between 6.0 and 6.5)"