Efficacy of 10% w/v fipronil spot-on against tick (Rhipicephalus sanguineus) infestation on Cats

Abstract

The efficacy of 10% w/v fipronil spot-on for treatment and prevention of Rhipicephalus sanguineus infestation on cats was examined. Twelve cats were randomly allocated into two groups which were the treatment and control groups. The treatment group received 10% fipronil spot-on at a dosage of 6.7 mg/kg on day 0. A group of 60 R. sanguineus was released to feed on each cat on days -7, -2, 3, 7, 14, 21, and 28. The ticks were counted and removed on days -4, 3, 6, 10, 17, 24, and 31. The infested ticks on the cats were also counted but not removed on day 0. Geometric mean number of tick infestation in the control group ranged from 20.83 to 26.17 ticks per cat, or the attachment rate of 34.72 to 43.62% and the mean attachment rate of 39.41%. Geometric mean number of tick infestation in the treatment group on the days before fipronil was applied on the cats ranged from 24.50 to 25.83 ticks per cat, or the attachment rate of 40.83 to 43.06% and the mean attachment rate of 41.95%. Percentages of the efficacy of fipronil used in this study were 99.24, 100, 100, 100, 99.18 and 99.24% on days 3, 6, 10, 17, 24, and 31, respectively. There were statistically significant differences between the geometric mean numbers of tick infestation between the control and treatment groups on days 3, 6, 10, 17, 24, and 31.