Margaret E. Derry is an adjunct professor of history at the University of Guelph, Ontario, and an associated scholar in the Institute for the History and Philosophy of Science and Technology, University of Toronto. She is the author of Ontario's Cattle Kingdom: Purebred Breeders and Their World, 1870–1920.

How did animal breeding emerge as a movement? Who took part and for what reasons? How do the pedigree and market systems work? What light might the movement shed on the assumptions behind human eugenics? In Bred for Perfection, Margaret Derry provides the most comprehensive and accessible book yet published on the human quest to improve and develop livestock. Derry, herself a breeder and trained historian of science, explores the "triangle" of genetics, eugenics, and practical breeding, focusing on Shorthorn cattle, show dogs and working dogs, and one type of purebred horse, the Arabian. By examining specific breeders and the animals they produced, she illuminates the role of technology, genetics, culture, and economics in the system of purebred breeding. Bred for Perfection also provides the historical context in which this system arose, adding to our understanding of how domestication works and how our welfare-since the dawn of time-has been intertwined with the lives of animals.