Laboratory Animal Medicine, Fourth Edition - A volume in the American College of Laboratory Animal Medicine (ACLAM) blue books series - is the most authoritative reference on Laboratory Animals biology, health, and care. Edited by recognized experts in laboratory animal science, endorsed as the official material for certification by ACLAM, this reference defines the standard for all aspects of humane animal use and scientific investigations. This new edition implements significant changes in the area. The Animal Welfare chapter moved to the beginning of the book, highlighting this subject's importance, and was expanded to include Euthanasia, previously covered on the anesthesia chapter. Further updates include the addition of hamsters & gerbils to the Guinea Pig chapter, the woodchuck and chinchillas are now included in the other rodents' chapter, instead of a dedicated chapter. The non-human primates' chapter was separated into two chapters: New and Old-World primates. The zebra finch and quail chapters were combined and now also include pigeons. The chapter on genetically modified animals was expanded to include additional CRISPR manipulation and genetic monitoring in key model species. The Microbiome Research chapter was added to account for this key factor and its importance in research. A chapter on transplant medicine was added and also covers xenozoonoses. The species-specific chapters are written at a level suitable for veterinarians and research scientists. Management chapters are suitable for program directors and facility managers both in academic and corporate settings. This edition continues the tradition of Laboratory Animal Medicine in setting the standards for the Laboratory Animal Science community, expanding, and updating the coverage following current and future practice in the area.