Pet food is pet food. Human food is human food, and never the twain shall meet, right? Not according to Marian Nestle. She’s a nutritionist at New York University, blogger and author of several books about food.

In her recent book Pet Food Politics: The Chihuahua in the Coal Mine, Nestle describes how the food Fido and Socks eat often contains the same ingredients consumed by farm animals. You know, the chickens, hogs and cattle that eventually end up in supermarkets and our dinner plates.

Worldview sat down with Marian Nestle recently. She told us how the pet food recall of 2007, that killed thousands of animals—illustrates how little is known about food production and the ripple effect that one contaminated product or processing plant can have on the entire food supply.