In case you haven't heard, Blue Buffalo was sued last year by Purina for false advertising. Here's my post about it from May 2014. Blue's initial response was akin to their typical techniques of using slander and inflammatory language to defend themselves. After exactly one year to the day, Blue admitted in court that their foods contained by-product meal. You can read more here: Blue Buffalo Admits to By-Products in Food.
Once again, there is nothing inherently bad about by-products. By-products are just food materials that are not used by the human food chain and can be very nutritious, especially by-product meals which are inherently concentrated sources of protein. They are used commonly in pet food because they are a readily available "cheap" source of animal protein. I put the word cheap in quotes because if you compare the amount of protein in a meal to the amount of protein in a cut of meat, say a chicken breast, you would need more chicken breast to meet the same amount of protein that is in the meal and since the breast is higher priced to begin with (because it is desired by the human food chain) it would be substantially more money. That would make pet food much more expensive than it is already. Blue, who has up until this point claimed that only whole cuts of meat are used in their foods, and who charges a pretty penny for their foods, was using by-products just like all of the other companies who they have maliciously slayed in their advertising.
Blue now claims that they didn't know that there were by-products in the foods they were selling as by-product free, and blamed their suppliers. I'm not sure which is worse - not actually owning up to your mistakes and apologizing for them, or not actually knowing what is going into your product, which you sell to unsuspecting pet owners to feed actual pets. Either way, throwing companies that work for you under the bus is another dick move, but one that is wholly unsurprising from Blue.
Lastly I have heard that Blue now has reps they will be sending to veterinary offices to try to get vets to recommend their food. Ha! I'll try to record that conversation if it happens. Should be pretty entertaining.