author(s)
M Kumar, SN Yadav, S De, MN Singh, J Roy, AK Nath and MP Baishya

abstract
A total of 32 clinical cases of cows infested with Rhipicephalus spp. ticks were divided into four groups with eight animals in each group. Group A were given weekly tape water bath for 3 consecutive weeks whereas group B, group C and group D were applied externally keetguard liquid, deltamethrin 12.5% and amitraz 12.5% at their recommended dose at weekly intervals for 3 consecutive weeks. Amitraz or keetguard treated groups showed complete knock down of all ticks from cows after 2^nd weeks of application while deltamethrin treated groups revealed complete knock down of ticks after 3^rd weeks of application. Treatment with keetguard showed 66.02% and 100% efficacy while amitraz treatment showed 77.08% and 100% efficacy against ticks on the seventh day and fourteenth day, respectively compared to day 0 values. However, deltamethrin treated cows revealed 54.08%, 96.60% and 100% efficacy against ticks on day 7, day 14 and day 21, respectively compared to day 0 values. Amitraz and keetguard showed comparable in-vivo efficacy against tick infestation in cows.