Shared pastures and anthelmintic resistance in wildlife and livestock

Normal 0 21 false false false /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Liberation Serif",serif; mso-fareast-font-family:SimSun; mso-ansi-language:EN-GB; mso-fareast-language:ZH-CN;} Parasitic diseases are an important threat to grazing livestock. Until recently, the most accepted control methods were regular, herd-level deworming regimen and grazing on “clean” or “safe” pasture. Presence of wild ruminants on pastures was considered as the main risk of parasitic infection. In the last decades, the failure of these conventional attitude was suspected. This study was carried out in Hungary, where springtime, whole-herd deworming is still in practice. Our hypotheses were that the above-mentioned strategy led to high prevalence of anthelmintic resistance; on the other hand, wildlife could not contribute to deleterious parasitosis of livestock. For this, we accomplished an investigation in the close surroundings of typical sheep herds. The aims were to determine the species structure and anthelminthic resistance in the parasite community of the sheep herds and the adjacent roe deer population. As a result, we found that in the roe deer (N=53), a more diverse parasite community exists and the most devastating worm species, Haemonchus contortus plays a less important role in it; than in the sheep (N=40). Prevalence of benzimidazole resistance in H. contortus was 17.1% and 68.6% in the roe deer and sheep, respectively. Our findings suggest that routine deworming cannot succeed; while presence of roe deer is rather useful, as its parasites attenuate the simplistic, anthelmintic resistant pasture community.