01652nas a2200145   4500008004100000245013800041210006900179260000900248300001400257490000700271520113200278100001701410700002101427856005801448       1985                        eng d00aChlorpyrifos for control of the short nosed cattle louse, Haematopinus eurysternus (Nitzsch) (Anoplura, Haematopinidae) during winter0 aChlorpyrifos for control of the short nosed cattle louse Haemato  c1985  a361 - 3650 v493 a<p>Two groups (A and C) of range cows were treated in February with chlorpyrifos (16 mL Dursban 44/cow) for the control of heavy infestations of the short-nosed cattle louse. Group A was treated in 1977 and group C in 1979 and each treated group was compared with a separate untreated group. Some of the treated cows were identified as carriers of louse infestation (subgroups A1 and C1), while others were noncarriers (subgroups A2 and C2). The maximum level of reduction in louse populations was 99% at week 4 posttreatment in subgroup A1, 99% from weeks 2-16 posttreatment in subgroup A2, 92% at week 3 posttreatment in subgroup C1 and 100% at weeks 15-17 in subgroup C2. Clinically, the treated cows, which were anemic at the time of treatment, recovered from anemia during the posttreatment period of 25 weeks for group A and 17 weeks for group C. Remission of anemia also occurred in the two untreated groups, possibly because of natural summer decline in louse population. The treatment had no effect on the whole blood cholinesterase of the cows and the treated cows showed no signs of organophosphorous toxicity.</p>
1 aKhan, M., A.1 aSchaalje, G., B.  uhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC1236193/