This is the Second Edition of a well-received book that reflects a fresh, integrated coverage of the concepts and scientific measurement of stress and welfare of animals including humans. This book explains the basic biological principles of coping with many forms of adversity. The major part of this work is devoted to explaining scientifically usable concepts in stress and welfare. A wide range of welfare indicators are highlighted in detail with examples being drawn from man and other species. The necessity for combining information from disciplines is emphasized with a one-health, one-welfare approach. This information forms the basis for a synthesis of new ideas. Among the issues covered are: - How brain and body systems regulate using feelings, physiological responses, behaviour and responses to pathology - Limits to adaptation - Assessing positive and negative welfare during both short-term and long-term situations - Ethical problems and suggested solutions A proper assessment of animal welfare is essential to take informed decisions about what is morally acceptable in terms of practice and in the development of a more effective legislation. This work encapsulates a very wide body of literature on scientific aspects of animal welfare and will thus prove a valuable asset for animal welfare scientists, psychologists, students and teachers of all forms of biology, behaviour, medicine, veterinary medicine and animal usage.