Dr. Hartsfield has served as a professor and associate department head of Veterinary Small Animal Medicine and Surgery at Texas A&M College of Veterinary Medicine since 1991. He began his teaching career at the university in 1973 and has spent the last 27 years in various faculty roles at Texas A&M and the University of Illinois College of Veterinary Medicine. Dr. Hartsfield earned his degree in veterinary medicine from Texas A&M in 1971. He then completed a master's degree and residency in veterinary anesthesiology in 1973 from Michigan State University College of Veterinary Medicine. He became a diplomate of the American College of Veterinary Anesthesiologists in 1976.