Thomas Alexander Killick qualified as a member of the Royal College of Veterinary Surgeons (MRCVS) of Edinburgh in 1878. On 30 October 1878 he was appointed as veterinary surgeon on probation in the Veterinary Department of the British military. The next year he was on active service with his regiment in Natal during the Anglo-Zulu War. His work during this time formed the basis of his "Clinical notes on the South African horse-sickness", published in the Veterinary Journal (Vol. 11, p. 312-320) in 1880.