David Besselsen, DVM, PhD, is the Director of University Animal Care (UAC), the Attending Veterinarian. He is a board-certified veterinary specialist (Diplomate) in the American College of Laboratory Animal Medicine and the American College of Veterinary Pathology, and served as Interim Dean for the College of Veterinary Medicine from 2017-2019. In addition to his administrative and service responsibilities, Dr. Besselsen is actively engaged in research through the provision of comparative pathology support for rodent models and oversight of the gnotobiotic mouse service. He has directed UAC Pathology Services since his arrival in 1995 and has over 80 peer-reviewed publications. UAC Pathology Services provides diagnostic and comparative pathology support for the research animals and research animal facilities at the University of Arizona. Capabilities include hematology, blood chemistry, necropsy, histologic preparation and interpretation, and others.