By Rick L. Cowell, DVM, MS, MRCVS, DACVP, Veterinary Clinical Pathologist, IDEXX Laboratories, Inc., Stillwater, OK; Ronald D. Tyler, DVM, PhD, DACVP, DABT, Adjunct Professor, Department of Anatomy, Pathology, and Pharmacology, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK; James H. Meinkoth, DVM, PhD, DACVP , Professor, Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK; and Dennis B. DeNicola, DVM, PhD, DACVP, Clinical Pathologist, Chief Veterinary Educator, IDEXX Laboratories, Inc., Westbrook, ME |