So in my ongoing quest for knowledge (actually I was bored on my Sunday overnight) I attended a recent rounds session from the american college of veterinary dermatology... and learned something VERY interesting about cross-contamination in canine diets...
A recent study, funded by the ACVD (not big food companies) tested numerous prescription and OTC diets for the presence of Soy protein in the diet. Three of the four OTC 'no soy' claiming diets were positive for soy antigen (Blue Buffalo Basics salmon and potato, Taste of the Wild Prairie bison and venison, Canidae salmon); Both TOTW and Canidae contained >25 ppm of soy antigen. While it is unknown how many ppm are required to trigger an allergy in dogs, it only takes 10ppm of soy to trigger an allergic response in a soy allergic human.
I will have to try to find the original study to find out which OTC diet tested negative for soy. Here's the study if anyone wants to try to beat me to it. "ELISA testing for soy antigens in dry dog foods used in dietary elimination trials" by C. Willis-Mahn, D. Raditic, K. Tater, and R. Remillard
This makes me sad, because now I have no choice but to recommend prescription diets for diet trials...
