Veterinary entomology, colonial science and the challenge of tick-borne diseases in South Africa during the late nineteenth and early twentieth centuries.

This article provides an historical overview of developments in veterinary entomology during the late nineteenth and early twentieth centuries. During that period state employed entomologists and veterinary scientists discovered that ticks were responsible for transmitting a number of livestock diseases in South Africa. Diseases such as heartwater, redwater and gallsickness were endemic to the country. They had a detrimental effect on pastoral output, which was a mainstay of the national economy. Then in 1902 the decimating cattle disease East Coast fever arrived making the search for cures or preventatives all the more urgent. Vaccine technologies against tick-borne diseases remained elusive overall and on the basis of scientific knowledge, the South African state recommended regularly dipping animals in chemical solutions to destroy the ticks. Dipping along with quarantines and culls resulted in the eradication of East Coast fever from South Africa in the early 1950s. However, from the 1930s some ticks evolved a resistance to the chemical dips meaning that diseases like redwater were unlikely to be eliminated by that means. Scientists toiled to improve upon existing dipping technologies and also carried out ecological surveys to enhance their ability to predict outbreaks. Over the longer term dipping was not a panacea and ticks continue to present a major challenge to pastoral farming.