Daniel Kehoe qualified (MRCVS) at Balls Bridge College, Dublin, in 1909 and was appointed research officer at the Onderstepoort Veterinary Research Institute by Sir Arnold Theiler* in 1910. He carried out research on a variety of subjects, including anthrax and toxic plants such as Cotyledon spp. His early work at Onderstepoort was reported in "Notes on some of the symptoms produced in healthy cattle by the use of certain alkaloids" and "Preliminary notes on the poisonous properties of Cotyledon orbiculata", both in the Second Report of the Director of Veterinary Research (1912, pp. 222-265 and 387-397). In 1915 he was put in charge of the production of a local vaccine against anthrax. An account of his work, including the history of the disease in South Africa, was published in "Anthrax in South Africa" (Fifth and Sixth Reports of the Director of Veterinary Research, 1918, pp. 209-255). On the whole his results with the vaccine were not very satisfactory, mainly because of its lack of immunising power.
Kehoe became a member of the Transvaal Veterinary Medical Association in 1910 and served on its council from 1914 to 1918, during the last two years as honorary secretary. His membership was transferred to the South Africam Veterinary Medical Association when the latter was established in 1920. The two papers he read before the association dealt with "The sero-diagnosis applicable to diseases of stock in South Africa" (1912, published in the Report of the South African Association for the Advancement of Science for 1912), and "Vaccination against Anthrax in South Africa" (1918). Another paper by him dealt with "The influence of the climatic and tellurical factors on the distribution and spread of certain animal diseases..." (Report of the South African Association for the Advancement of Science, 1915). He also participated actively in the proceedings of the Transvaal Biological Society (1907-1916), reading three papers before it on "The poison efects of Cotyledon" (1912), "The red blood corpuscle" (1913), and "The cultivation of tissue in vitro" (1914). In the latter year he served as the society's president. He became a member of the South African Association for the Advancement of Science in 1912. In 1916 became a foundation member of the South African Biological Society, serving as president of its Pretoria Branch the next year. He was elected an honorary member of the society in 1919. Meanwhile he was put in charge of the Allerton laboratory in Natal in 1916, but in October 1918 resigned to take up the position of professor of pathology, histology and bacteriology at the Veterinary College of the University of Dublin. He remained there until his death in 1928. From 1921 onward he published a number of veterinary papers in collaboration with J.F. Craig.