Bad ingredients equal bad dog food. Pet food ingredients are regulated by two sources: the American Feed Control Officials (AAFCO), which decides what nutrients animal food should contain, and the Food and Drug Administration (FDA), which determines the quality of ingredients. However, “quality” can be relative, and the FDA approves ingredients for animal food that may actually be dangerous for your dog.

For instance, there are no regulations prohibiting ingredients from “rendering facilities,” where dead animals are broken down for use in other products. Rendering facilities handle everything from dead livestock to expired meat, “It’s almost impossible to tell what’s being rendered: it can be road kill, zoo animals, and sometimes even spoiled meat from the grocery store that’s still wrapped in plastic.” You wouldn’t want to eat that stuff, so why would you feed it to your dog?