In addition to excellent observation skills and a good understanding of production medicine, veterinarians require the tools of epidemiology for the successful investigation of disease outbreaks. Food supply veterinary practitioners are often called upon to investigate various types of disease outbreaks. In this article, the authors outline the primary questions a practitioner should address and summarize a systematic approach to determining the causes of an outbreak and minimizing further losses. The investigation of disease outbreaks provides an opportunity for the herd veterinarian to show clients the advantages of a herd health program and the value of a good record-keeping system.