SPECTRUM OF ACTIVITY OF DORAMECTIN AGAINST CATTLE MITES AND LICE

A series of 16 studies was conducted involving 288 cattle with natural ly acquired or experimentally induced mite or louse infestations to ev aluate the efficacy of doramectin. Four studies were conducted against the mite species Psoroptes bovis and two against the mite species Sar coptes scabiei. Ten studies involved cattle with one or more of the fo llowing louse species: Damalinia bovis, Haematopinus eurysternus, Lino gnathus vituli and Solenopotes capillatus. In each study, a group of a t least nine but not more than 25 cattle were randomly allocated to a control or a treated group. One group was treated with doramectin at 2 00 mug kg-1 and the other group received no medication. Mites or lice were quantified by species immediately before treatment and at weekly intervals for 4 weeks thereafter. Doramectin was 100% efficacious agai nst infestations of P. bovis, Sarcoptes scabiei, H. eurysternus, L. vi tuli and Solenopotes capillatus. The drug reduced infestations of D. b ovis by a mean of 82%.