Augustus Frederick Harber qualified as a veterinarian (MRCVS) at the Royal College of Veterinary Surgeons in London in 1897 and won the Fitzwygram prize as the student who obtained the highest marks in the final examinations that year. In September 1903 he was recruited for appointment as district veterinary surgeon to the Civil Veterinary Department of the Natal Government and subsequently the South African Civil Service. He served in this capacity to 1920 and was stationed at Pietermaritzburg, Darnall, Durban, and Greytown. While at Pietermaritzburg he lectured in veterinary science at the Cedara Agricultural College. During this period he published articles on "Swine fever" (Natal Agricultural Journal, 1904, Vol. 7, pp. 737-738) and "Epizootic lymphangitis and its treatment" (Agricultural Journal (Union of South Africa), 1913, Vol. 6, pp. 504-506). He was a member of the South African Veterinary Medical Association from 1920.
After retiring from government service Harber took up private practice in Mooi River until 1938 when he was employed by the Durban Municipality as veterinary officer and lecturer/demonstrator in meat inspection. In 1947 he returned to private practice until he finally retired in 1955. Harber had a distinguished military career, serving in both the Anglo-Boer War (1899-1902) and World War I (1914-1918). During the latter he was attached to the Natal Mounted Rifles and in August 1918 was awarded the Distinguished Service Order (DSO). In civilian life he became known as the producer of "Harber's Gallsickness Antitoxin", a popular home remedy consisting of formalised gall collected from cattle from the Golela area (on the Transvaal-Swaziland border) slaughtered at the Durban abattoir. He was married to Dorothy V. Smithwick. After her death in 1920 he married Mabel L. Keeling (born Moorby)