The third edition of The Beast Within has been updated throughout to include current scholarship, new discussion of definitions, and fresh perspectives on critical animal theory that places animals, rather than humans, at the center of the discourse.

Organized thematically, Salisbury incorporates many new sections and subsections to reveal the multifaceted history of the relationship between humans and animals: domestication, animal diseases and pandemics, dogfights, cockfights, Islamic dietary restrictions, menageries and zoos, and animals as entertainers. To show how modern concerns have been informed by medieval precedents, sections have been expanded to uncover medieval understandings of animal sexuality, animals before the law, and vegetarianism and modern 'fake meat'. The logical narrative concludes with chapters on 'Animals as Humans' and 'Humans as Animals', demonstrating that the lines between humans and animals have become increasingly blurred from the fourth to the twenty-first century.

With an interdisciplinary approach that discusses humans and animals in relation to domestication, symbolism, science, law, religion, food and diet, sexuality, and entertainment, The Beast Within is an essential resource for all students of animal history, literature, and art in the Middle Ages.