Why are corn, wheat, soy, byproducts in dog food considered bad?
Again, there is no known problem with these ingredients. The stigma about byproducts is especially annoying, because byproducts like liver, kidney and other organs have great nutritional value compared with meat.
The reason behind the stigma is not easy to understand. It really has to do with a series of non- professionals speculating on unsupported theories and then spreading the information as if it's truth. The same happens with people...just look at all the fad diets that come and go.
While there may be some shred of evidence that these ingredients may have potential to cause harm, there is not nearly enough for a professional to say that they are bad and other ingredients are good.
You can see that the pet food industry has responded to the unsupported claims of grains, natural ingredients, byproducts and even raw food, but please don't take that as confirmation that these ingredients are bad or good. It's nothing more than sales strategy and responding to consumer demands.
This is a huge topic that I cannot begin to cover here, so I'll give you a couple links to some helpful articles:
https://www.petcoach.co/article/what-to-look-for-when-choosing-your-pet-s-food
https://www2.vet.cornell.edu/news/20130205/what-pet-food-should-i-feed
Updated on September 23, 2025