"Healing the Herds: Disease, Livestock Economies, and the Globalization of Veterinary Medicine" offers a new and exciting comparative approach to the complex interrelationships of microbes, markets, and medicine in the global economy. It draws upon fourteen case studies from the Americas, western Europe, and the European and Japanese colonies to illustrate how the rapid growth of the international trade in animals through the nineteenth century engendered the spread of infectious diseases, sometimes with devastating consequences for indigenous pastoral societies. The intensification of agriculture has transformed environments, with consequences for animal and human health. The last two centuries have also witnessed major changes in the way societies have conceptualized diseases and sought to control them. Politics, economics, and science inform these essays on the history of animal diseases and the expansion in veterinary medicine.