The questions you ask cannot be properly addressed with simple answers. The answers are, however, contained in the links sent to you. We may seem evasive, but that is because the question is leading to and can result in improper conclusions in light of the method of feeding Wysong advises.
As stated in the meats article, the availability and quality of non-GMO, free range, and organic ingredients is variable. We cannot, therefore, reliably obtain these ingredients. However, if feeding is approached by the method explained in the Optimal Health Program™
, dangers are minimized. All Wysong products are tested before release into the market, but we cannot guarantee that the products are 100% "toxin" free since virtually no animal or human tissue can be tested and found to be completely free of any potentially toxic, ubiquitous substance. But remember, the dose makes the poison. See Toxin Paranoia: http://www.wysong.net/pet-health-and-nutrition/toxin-paranoia.php