This article traces a conflict between the experts and the supervisors of the French Food Safety Agency (AFSSA) in December 2004. This conflict was focused on Q Fever, an animal disease that is transmitted from animals to humans in conditions that remain obscure, as the infectious agent can propagate through the milk or be airborne. This conflict allows us to show how the agency is hierarchically organized, and how the writing of recommendations and reports reflects this hierarchy and its conflicts. These conflicts can be understood only in the background of the mad cow disease that profoundly structured the field of food safety in France by focusing it on zoonosis.