Can Amblyomma tick infestations be controlled on goats using Tick Grease (Cypermethrin) in a comparative field trial in the area of Mnisi (Mpumalanga), South Africa?

Abstract

The present study was conceived with as main objective to establish more insight in the effectiveness of the acaricide, Tick grease, on indigenous goats in the Mnisi area (Mpumalanga), South Africa. All fifty goats examined for tick infestations, twenty-five belonging to the control groups and twenty-five belonging to acaricide treatment groups, were infested with ticks. The total number of collected ticks was 3401, of which the majority were immature ticks (709 adults, 132 nymphs and 2560 larvae). Three Ixodid tick species were found during these examinations. The predominant tick was Hyalomma marginales rufipes (n=682) followed by Amblyomma hebraeum (n=81) and finally Rhipicephalus (Boophilus) microplus (n=78). The PCR results show that 0% of female adults and 20% of the male adults are positive for E. ruminantium. Of all tested nymphs, 24.2% were infected with E. ruminantium. Besides E. ruminantium some of the samples also tested positive for Anaplasma (n=2), Neoehrlichia (n=2), Theileria/Babesia (n=2), other Theileria spp (n=4) and Babesia spp (n=1). The effects of tick grease did temporarily reduce the number of ticks infesting the goats in the Mnisi area. In most cases it seems that the effect of collecting ticks and the effect of tick grease gradually decreases during the examination weeks. It can there for be concluded, that in general, tick grease does decrease the tick/ goat ratio one week after treatment before the ratio gradually increases over the following weeks. More research should be done on the resistance and the effect of tick grease on ticks. It may be that other acaricides prove to be more effective than tick grease. It would also be advisable to do more research on alternative acaracide effects. Goats always will play an important role in maintaining tick infestations and will always need to be included in any tick control programme. More important is to prevent disease outbreaks of heartwater through overusing acaricides and continuing to inform farmers on the results and methods of possible sustainable, cost-effective and strategic tick control.