R. Cecil Cochrane was the son of John Cochrane and his wife Martha, born Little. He received a private education at Armagh, County Donegal, Northern Ireland. In 1897 he qualified MRCVS (London) and came to South Africa during the Anglo-Boer War (1899-1902) as a regular officer in the Army Veterinary Department. He served in Natal from 22 April 1899 to 7 December 1905, earning both the Queens Medal (4 clasps) and the Kings Medal (2 clasps). During 1900 he acted as senior veterinary officer and in 1903 was seconded to the Transvaal Civil Veterinary Department for a year. In 1905 he returned to England. He published a paper on 'Glanders in South Africa' (Journal of Comparative Pathology and Therapeutics, 1902), but his main contribution was combatting East Coast Fever, which also formed the subject of his published FRCVS thesis.
Cochrane served in the military again during World War I (1914-1918), rose to the rank of lieutenant-colonel, and was honoured as a Commander of the Order of the British Empire (CBE). He retired from the military in 1925. In 1903 he married Lily Holmes Tennant.