The UC Davis School of Veterinary Medicine (SVM) is saddened to announce the passing of Dr. Timothy O’Brien on July 26, 2021. Professor of Radiology and Diplomate of the American College of Veterinary Radiologists (ACVR), Dr. O’Brien served on the SVM faculty for 39 years. After receipt of a DVM from the University of Illinois (’65), he completed an internship at Washington State University, and then MS (’67) and PhD (’69) degrees in radiology and radiation biology at Colorado State University. In 1969, Dr. O’Brien joined the UC Davis faculty as an Assistant Professor of Veterinary Radiology and Assistant Research Radiologist in the Radiation Biology Laboratory and obtained ACVR specialty board certification.

A tireless champion for the SVM’s growth and its reputation, Dr. O’Brien served as Associate Dean for Student Services, and then for more than a decade as Chair of the Department of Radiological Sciences, and later as Chair of Surgical and Radiological Sciences. Throughout much of his early career, he was also Service Chief and Director of the residency program for the teaching hospital’s Diagnostic Imaging Service. Under his leadership, Radiological Sciences evolved to add faculty expertise in radiation therapy, nuclear medicine, ultrasonography, and cross-sectional imaging (CT, MRI), and the residency program expanded, becoming recognized as the premier veterinary diagnostic imaging training program globally.

Initially as one of three faculty radiologists, Dr. O’Brien provided interpretation for small and large animal patients. Drawing on his clinical experiences, he wrote the first veterinary radiology reference text on abdominal disorders in 1978, Radiographic Diagnosis of Abdominal Disorders in the Dog and Cat: Radiographic Interpretations, Clinical Signs, Pathophysiology. However, the hospital’s expanding equine caseload honed his early career interest in equine orthopedic disease, and he quickly developed expertise in equine imaging, devoting most of his career to understanding equine musculoskeletal disease through improved imaging techniques and studying the pathophysiology of joint disease. Highlights of his scholarship were development of special projections to evaluate disorders of the carpal, navicular, and pedal bones, and the fetlock, stifle, and tarsal joints of horses. Many of the radiology, equine surgery, and equine medicine residents he mentored in clinical research became faculty at UC Davis and other U.S. and international veterinary schools.     

Dr. O’Brien taught the first course in large animal radiology at UC Davis and subsequently in collaboration with Drs. Roy Pool, Dennis Meagher, and Sue Stover, developed an elective course in equine lameness that was one of the first integrated courses in the DVM curriculum. He was passionate about continuing education and improving the quality of equine radiographs and devoted countless hours to preparing and delivering the highly acclaimed Equine Lameness Panel at the American Association of Equine Practitioners (AAEP) annual meeting. In 1979, with his wife Janet, he founded and directed for more than four decades the popular annual Lake Tahoe Equine Disease Conference. After the death of the long-time SVM farrier, Dr. O’Brien established the school’s first named lecture in 1987, the Charles Heumphreus Memorial Lectureship, and raised the funds to endow this free continuing education program for farriers. In 2005, he published a monograph O'Brien's Radiology for the Ambulatory Equine Practitioner, written specifically to guide equine ambulatory veterinarians in the acquisition of high-quality radiographic images of equine limbs. The AAEP recognized Dr. O’Brien with their 2008 Distinguished Educator (Academic) Award.

Throughout his career, Dr. O’Brien was a strong proponent for the importance of research, serving for many years on the school’s Equine Research Laboratory (now, Center for Equine Health) Scientific Advisory Committee and nationally on the Grayson-Jockey Club Foundation Scientific Committee, including five years as Chair.

Dr. O’Brien was a formidable advocate for ensuring the SVM remained on the forefront of imaging technology and faculty expertise in diagnostic imaging. His many leadership and scholarship contributions and the realization of his vision for diagnostic imaging is an enduring legacy, foundational to the sustained excellence of the school’s diagnostic imaging programs.

Tim was devoted to his wife Janet, sons Michael (an MD Interventional Radiologist) and Shawn (deceased), and grandchildren Christina, Kelly, William, and Sophia – all of whom he loved dearly. A family service will be held in Illinois.

The SVM celebrates Dr. O’Brien’s accomplishments and is saddened by his loss. Our thoughts are with his family at this time.