0 Rothwell, J. T. Hacket, K. C. Ridley, I. Mitchell, L. Donaldson, C. Lowe, L. B. 1999 Australian Veterinary Journal 77 4 255-258 Apr 45072 Administration, Cutaneous Animals Cattle Cattle Diseases insecticide Lice Infestations/drug therapy/prevention & control/veterinary Mallophaga Pyrethrum Treatment Outcome OBJECTIVE: To assess the efficacy of zeta-cypermethrin pour-on to control cattle lice. DESIGN: Five field trials in south-eastern Australia. PROCEDURE: Zeta-cypermethrin pour-on, deltamethrin pour-on and pour-on vehicle were applied to groups of 10 cattle. Lice were counted before treatment and 14, 28, 42 and 56 days after treatment. RESULTS: Zeta-cypermethrin pour-on given at 2.5 mg/kg was equivalent to, or marginally more effective than a deltamethrin pour-on at 0.75 mg/kg. It eliminated B bovis and H eurysternus and gave good control of L vituli and S capillatus. Zeta-cypermethrin at 1 mg/kg gave good control of B bovis and H eurysternus but was not satisfactory against L vituli and S capillatus. CONCLUSION: Zeta-cypermethrin pour-on, given at 2.5 mg/kg, is an effective treatment for cattle lice control. Zeta-cypermethrin, and other synthetic pyrethroid pour-ons, are the treatment of choice to control B bovis. LR: 20041117; JID: 0370616; 0 (Insecticides); 0 (Pyrethrins); 52315-07-8 (cypermethrin); ppublish0005-0423 Journal