Thomas H. Dale qualified (MRCVS) at the New Edinburgh Veterinary College in 1889 and immediately came to South Africa as a civil veterinary surgeon (CVS) attached to the Army Veterinary Department. In October 1903 he joined the Veterinary Division in the Department of Agriculture of the Transvaal Colony. By 1908 he was district veterinary surgeon for Potchefstroom, Wolmaranstad and Bloemhof. That year he published a paper on "Two undescribed diseases of sheep" in the Veterinary Record. The diseases were gousiekte and pulpy kidney (enterotoxemia). Later he contributed a paper on "A bone disease of fowls" (1913) to the same journal. In 1914 he was a government veterinary surgeon in Mossel Bay. Following the outbreak of World War I (1914-1918) he was appointed to commissioned rank in the Active Citizen Force in 1916. He later relocated to Natal, where he died in service in Durban. He published some short papers aimed at the farming community in the Transvaal Agricultural Journal (1904, 1906/7) and the Agricultural Journal of the Union of South Africa (1911, 1912).
Dale joined the Transvaal Veterinary Medical Association in 1903, the year it was founded. He served on its council from 1906 to 1914, and as president from 1907 to 1909. He delivered one of several contributions on "Piroplasmosis of the donkey" before its members in September 1903 (published in the Journal of Comparative Pathology and Therapeutics that same year), and in September 1907 read a paper on "Two undescribed diseases of sheep".