Sam B. Woollat qualified as a veterinarian (MRCVS) in London in July 1897. He came to Natal that same year, having been appointed in October by the Natal Veterinary Department. After being stationed in Pietermaritzburg until November 1898 he succeeded J.W. Baxter* in Durban. In October 1901 he was appointed principle veterinary officer for Natal at the age of 25, succeeding H. Watkins-Pitchford*. He was stationed in Pietermaritzburg.
From 1900 to 1906 Woollat published a number of articles in the Natal Agricultural Journal on a variety of animal diseases, including worm in sheep (1900), Glanders and Horse Mange (1902), East Coast Fever (1905, 1906), plant poisoning (1905), and Redwater (1906). In 1904 he represented the Natal Colony at the Inter-Colonial Veterinary Conference on animal diseases in South Africa, held in Cape Town. By 1906 he had 14 District Veterinary Surgeons under him, including S.T.A. Amos*, A.F. Harber*, F. Hutchinson*, W.M. Power*, F.A. Verney*, and J.L. Webb*. He qualified as FRCVS in 1905.
In 1908 Woollat resigned in favour of farming, but subsequently became managing director of Federated Meat Industries in Durban until 1932. From 1914 to 1919 he was president of the Natal Agricultural Union. He also served on a commission appointed by the Prime Minister, General J.C. Smuts*, to evaluate conditions in South West Africa (now Namibia) following South Africa's occupation of the territory during World War I (1914-1918). He was a member of both the Transvaal and Natal Veterinary Medical Associations, and later of the South African Veterinary Medical Association.