[The effects of postparturient anthelmintic treatment on ewes and their lambs (author's transl)]

Anthelmintic treatment of ewes after lambing resulted in partial suppression of the spring rise in egg counts in Frisian milch-sheep, lambing early in March and a rather satisfactory suppression of the spring rise in Texel ewes lambing late in March. The Frisian and Texel sheep were treated with 44 mg/kg and 66 mg/kg thiabendazole respectively. Beneficial effects of treatment were not observed in the ewes or their lambs compared with the controls. Particularly, treatment failed to produce any improvement of the gain in weight in the lambs. In the Frisian ewes, the haemoglobin content was determined at regular intervals. Both in the treated and in the untreated group, the haemoglobin content decreased significantly. Moreover, this decrease was correlated with the increase in faecal Haemonchus egg counts These results and those of previous experiments in conjunction with findings reported in the literature, lead to the general conclusion that farm management is highly decisive in answering the question as to how serious trichostrongylid and strongylid infections will be and the extent to which anthelmintic treatment of the ewes could have a beneficial effect.