A survey of the incidence and importance of the tick-borne diseases heartwater, redwater and anaplasmosis in the heartwater-endemic regions of South Africa.
265 questionnaires were send to leading farmers in Transvaal, Natal and eastern Cape areas to assess the incidence and importance of the tickborne diseases and attitudes of the farmers to control measures. 127 farmers responded and indicated that they were experiencing losses of 1.3, 0.3 and 0.2% in cattle due to heartwater, redwater and anaplasmosis, respectively. In sheep and goats, the heartwater mortality was 3.8%. Only 35% of cattle farmers and 15% of farmers keeping sheep and goats, vaccinated their animals against heartwater and 9% of the farmers claimed poor protection after immunization. Vaccination against redwater and anaplasmosis on 11.8 and 14.2% of farms, respectively, was considered to have no beneficial effect on the mortality rates of these diseases according to the farmers. The highest proportion of cattle farmers treated their animals with acaricides 21-25 times per annum, but most (34.8%) small stock owners treated their sheep and goats less than 6 times a year. 66.1% of farmers used synthetic pyrethroids, 15% formamidines, 15% pyrethroid/organophosphate combinations and only 3.6% organophosphates. Based on the information submitted in response to the questionnaire the farmers received advice concerning their tick control policies. 70 of the 127 farmers were advised to allow more ticks on their cattle.