Efficacy of ivermectin jetting fluid for control of the sheep biting louse (Damalinia ovis)

Abstract

Nine field trials were conducted to evaluate the efficacy of ivermectin jetting fluid applied by hand jetting against the biting louse, Damalinia ovis (also referred to as Bovicola ovis), in long-wooled sheep. The trials included 7632 sheep with 3-9 months wool growth. Louse counts were obtained periodically from 23-25 monitor sheep selected from each treated flock for up to 15 weeks after treatment. Overall reductions in louse counts at 4-6, 8-10, 11-13, and 15 weeks after treatment compared with pretreatment values were 98.7, 99.0, 98.9, and 99.8%.