Francis J. Dunning qualified (MRCVS) at Edinburgh in 1901 and came to South Africa during the Anglo-Boer War (1899-1902) to serve as a civil veterinary surgeon attached to the Army Veterinary Department until 1904. After his discharge from the army he remained in South Africa as a government veterinarian, first in the Transvaal (from June 1905) and from 1912 as district veterinary surgeon in the Veterinary Division (Department of Agriculture) of the Union of South Africa. In 1911 he obtained his FRCVS with a thesis entitled East Coast Fever. During World War I (1914-1918) he served in the East Africa campaign, after which he returned to the Veterinary Division until his retirement in 1934. Late in his career he published two papers in the Journal of the South African Veterinary Medical Association, on 'East coast fever and its irradication' (1929) and 'Two uncommon skin parasites' (1931).
Dunning was a member of the South African Veterinary Medical Association and in 1929 resided in Dundee, KwaZulu-Natal. After his retirement he practiced for a few years in Port Elizabeth. He was married to Ethel Gladys Baylis.