In recent years, the practice of using animals for biomedical research has come under severe criticism by animal protection and animal rights groups. Laws have been passed in several countries to make the practice more ‘humane’. Debates on the ethics of animal testing have raged since the seventeenth century. Theodore Roosevelt in the nineteenth century stated, “Common sense without conscience may lead to crime, but conscience without common sense may lead to folly, which is the handmaiden of crime.”