The history of IACUCs evolved from the history of regulation of animal welfare in the USA. Prior to 1963, regulation was conducted solely by investigators, and research laboratories had inconsistent animal care policies and standards of care. A group of veterinarians formed the Animal Care Panel and began work in 1961, and in 1963 they published the first edition of "The Guide for the Care and Use of Laboratory Animals", referred to hereafter as the Guide. Subsequent editions of the Guide were supported by NIH and published by the Institute of Laboratory Animal Research branch of the National Academy of Science. Currently, the Guide is in its eighth edition.