This book explores central aspects of genetic modification of animals for scientific purposes in the context technological possibilities, regulatory issues in different regions, animal welfare implications and wider ethical issues exemplified through current theories and frameworks. This discussion of lab animals produced through modern biotechnologies becomes increasingly pressing as CRISPR-Cas9 technology advances rapidly, challenging legal and ethical frameworks all over the world. Such animals are now affordable and readily available to almost every branch of scientific research. This not only raises enormous potential for creating ‘tailored’ models for human diseases but also rubs up against the traditional guiding principles (the 3Rs) for the humane use of animals for scientific experiments and raises wider ethical issues around death, integrity and naturalness. In this book, expert authors from diverse backgrounds in laboratory animal care, animal research, technology and animal rights explore a range of topics, from the science behind biotech research animals and the regulation of their use, to utilitarian, animal rights, virtue ethics and ethics of care, and critical animal studiers' perspectives on the use of these technologies. Whatever your background or role in animal research, this book will challenge and stimulate deeper consideration of the benefits, disadvantages and ethical consequences of the use of biotechnology in the animal laboratory.