Someone on Dachsie Bulletin Board posted this and thought it was interesting and highly gross.
"Not all by-products are bad as many of us have been told by some pet food makers. To illustrate this, a Proctor and Gamble employee (P&G owns Eukanuba) shared this story with me. When a truckload of chicken by-product arrives at the Eukanuba manufacturing facility, samples are taken from multiple places in the load and tested to ensure that it meets their standard. On one occasion a load did not meet their high quality standard and was sent away. An employee at the Eukanuba plant asked the truck driver where he was headed with their rejected by-product. The driver said he was taking it to a nugget plant. So, some chicken by-product that does not meet Eukanuba’s quality standard for dog food is still good enough to become chicken nuggets for you and your children."
(found at dogguide.net)