Efficacy trial of three pour-on acaricides on external parasites of cattle in Zaria, Nigeria

Abstract

External parasites cause adverse effects on livestock production globally. In a study to determine the efficacy of three acaricides, fifteen pastoralist herds were randomly selected. Each herd had a group with eight cattle and three other groups with four. All animals were screened for external parasites pre-acaricide application. Groups 1, 2 and 3 were assigned to 1% Fipronil (Topline^®), 0.5% Ivermectin and 5% Cypermethrin, respectively. Group 4 animals were untreated control. Observation of earmarked animals was twice weekly for seven weeks. Results showed that Musca domestica and Stomoxys sp died instantly and were repelled from herds for four weeks. No new tick attachment on experimental animals four weeks post application. Ticks were absent in Group 1 six weeks post application. Lice died 3 days post application in all experimental groups, while the animal with demodecocis in Group 1 had regression of lesions week 2 post application. Hair re-growth was observed in affected animals by week 4. Only a meager regression of demodecocislessions was observed in animals in other groups. The study demonstrated that the three acaricides had both therapeutic and prophylactic effects on external parasites, but Fipronil (Topline^®) had longer prophylactic and better curative effects than the other two acaricides. It is, therefore, recommended that Fipronil (Topline^®) should be reliably used for the control of external parasite in cattle because of its broader spectrum of activity and longer lasting effect.

Keywords: Efficacy; Topline^®; external parasites, Nigeria