[2] During the Second World War, Arbuthnott served in the near and Far East and Pacific theatre (1944–45) with the Fleet Air Arm of the Royal Navy (1942–46), and was awarded the Distinguished Service Cross (DSC) in 1945.

He served with the Agricultural Land Service division of the Ministry of Agriculture (1949–55), was Senior Land Agent for Nature Conservancy in Scotland (1955–67), member of the Countryside Commission (Scotland; 1968–71), Chairman of the Red Deer Commission 1969–75, President of the British Association for Shooting and Conservation (1973–92), President of the Scottish Landowners' Federation (1974–79), and a member of the Royal Zoological Society of Scotland (1976–2012), Scottish Agricultural Organisation Society (1980–1983),[1] the RSGS (1983–2012); Federation of Agricultural Co-operatives (UK) Ltd (1983–2012); Deputy Chairman of the Nature Conservancy Council (1980–85); and Chairman of the Advisory Committee for Scotland (1980–85).

[2] In 1985, Clydesdale Bank appointed Arbuthnott as a main board director, a position that lasted until 1992.

[5] Arbuthnott was Fellow of the Royal Society of Arts (FRSA) and a Fellow of the Royal Society of Edinburgh (FRSE), Prior of the Scottish Venerable Order of St John (GCStJ) (1983–95), and served as Lord High Commissioner to the General Assembly of the Church of Scotland (May 1986–87), on the Royal Commission on Historic Manuscripts (1987–94), and a member of the Aberdeen University Court (1978–84), and Liveryman of the Worshipful Company of Farmers.

Following Arbuthnott's death, a service of thanksgiving for his life was held at St Machar's Cathedral, Aberdeen, on 14 September 2012.