He was a graduate of the University of Pretoria, Onderstepoort Veterinary College, graduating in 1959. He undertook postgraduate research at the Avian Diseases and Oncology Laboratory in East Lansing, Mich., in 1961.
Over the next five years he succeeded in developing a practical Marek’s disease vaccine which became the basis of protection against this infection, which was responsible for significant loss in both egg and broiler industries. From 1974 through 1988, Dr. Purchase served as the assistant administrator of the National Program Staff and scientific advisor to the director of the Beltsville Research Center.
In 1988, he was appointed director of research and associate dean of the Mississippi State University College of Veterinary Medicine. He was a founding diplomat of the American College of Poultry Veterinarians and was a diplomat and president of the American College of Veterinary Microbiologists. He was chief of the Pennsylvania Veterinary Laboratory in Harrisburg, Penn., from 1998 until retirement in 2000.
During his career Dr. Purchase received several honors, including the 1971 Arthur S. Fleming Award and the USDA Distinguished Service Award.