A native of Alberta, Nielsen became an associate professor of pathology in 1964 at the newly formed Western College of Veterinary Medicine (WCVM) at the University of Saskatchewan. He subsequently became head of the department of pathology and then Dean of WCVM in 1974.

Nielsen served as the eighth dean of OVC from 1985 to 1994. During his tenure, he established the Department of Population Medicine and the Veterinary Teaching Hospital, now the Health Sciences Centre, and initiated OVC Pet Trust. He was also a key leader in establishing the Canadian Cooperative Wildlife Health Centre and developed the field of ecosystem approaches to health at the University of Guelph.

Nielsen is a professor emeritus from the University of Guelph.

“All of us at OVC extend our congratulations to Dr. Nielsen, who has been a true visionary in veterinary medical education,” says OVC Dean Jeff Wichtel. “This significant honour recognizes his many valuable contributions to veterinary medicine throughout his academic and administrative career, notably in livestock disease, in biomedical science, as well as his ongoing efforts in ecosystem health.”

The Order of Canada, one of the country’s highest civilian honours, was established in 1967, during Canada’s centennial year, to recognize outstanding achievement, dedication to the community and service to the nation. Over the last 49 years, more than 6 500 people from all sectors of society have been invested into the Order.