Douglas was born in Tillsonburg, Ontario and raised on the family farms along the north shore of Lake Erie, east of Port Burwell. Upon graduation from Law School at the University of Western Ontario, he attended the Bar Admission Course at Osgoode Hall in Toronto and was admitted as a member of the Law Society of Upper Canada in 1967.
During a distinguished career that began with his mentors, Edward O. Fanjoy (later the Honourable Justice Edward O. Fanjoy), and Murray J. Hennessey, he established his own firm, Gunn & Associates, in 1984. Douglas has enjoyed an exciting general law practice with an emphasis on civil litigation and with a specialty in claims of an agricultural nature. With the lapse of time, his litigation practice has developed more of an emphasis on estate litigation and the administration of estates in general.
At this time he is pleased to find himself representing the children and even the grandchildren of some of his earliest clients.
Douglas has served on the Board of Directors of the St. Thomas-Elgin General Hospital Foundation and has chaired the Planned Giving Committee of that hospital. He also sat as Chairman of the Ontario Crop Insurance Arbitration Board for a number of years, and has been a seminar leader at the Bar Admission Course. Douglas has continued his attachment to agriculture through his membership in the Canadian Hereford Association, the day-to-day management of a purebred cattle operation and his continued operation of the family farms in Norfolk County, where he has been active in the search for renewable energy through wind power. He has also been a member of the Elgin Group Police Services Board for a number of years.
Douglas is a member of the Elgin Law Association, Law Society of Upper Canada, Law Society of Alberta and Advocates Society.