One thing I know is soy is not digestable to animals so it is a filler for many breeds in their food. The probelm comes from how the seed and plant was treated as those checmical are digestable. It causes all sorts of probelms being one of the high allergy foods for animals and people. The differance between american soy and china soy is how it is grown. Our has been treated with growth hormones and pesticides so farmers here get top production. In china it is not treated or at least it was not until recentally.