The video by NaturalBalance’s president makes the problem a little clearer for users of that brand. In short, Diamond Foods is a co-manufacturer of several formulas for different dog food companies and Diamond’s facilities are the problem.
My dog’s food is home cooked fresh low-fat pork loin suplemented with a handful of Natural Balance’s potato and duck small bites.
here’s the video: http://www.naturalbalanceinc.com/home/NB_productFAQ.html