Resistance to @entity9158 anthelmintics in @entity1641 strongyles. 2. Evidence of side-resistance, and susceptibility of XXXX -resistant strongyles to non- @entity9158 compounds.

@entity1641 @entity73032 @entity61689 @entity11546 @entity9158 @entity73031 @entity46316 @entity73033 @entity7400 @entity29321 @entity18884
The susceptibility of a known @entity18884 -resistant population of small strongyles to anthelmintics of both @entity9158 and non- @entity9158 groups, was determined. In the first study, 42 @entity1641 infected with @entity18884 -resistant small strongyles were allocated to 6 groups. Treatment groups received one of the following anthelmintics: @entity7400 , @entity46316 , @entity46316 plus @entity11546 , @entity73031 , or a combination of @entity18884 , @entity29321 and @entity11546 . @entity73031 and the @entity18884 / @entity29321 / @entity11546 combination produced highly significant (p less than 0.001) reductions in faecal strongyle egg counts 20 days post-treatment. @entity7400 , @entity46316 and @entity46316 plus @entity11546 failed to reduce strongyle egg counts significantly. Larval culture and differentiation indicated that in all cases of anthelmintic failure, small strongyles of the sub-family Cyathostominae were involved. Eighteen @entity1641 from groups in which treatment had failed were re-allocated to 3 groups. Treatment with either morantel tartrate or @entity73032 was highly efficient in reducing faecal strongyle egg counts. In the final study, fifty-four @entity1641 , infected with @entity9158 -resistant small strongyles were allocated to 10 groups. On day zero, each treatment group received one of the following anthelmintics: @entity18884 , @entity61689 , @entity7400 , @entity73033 , @entity29321 , @entity18884 / @entity29321 , @entity61689 / @entity29321 , @entity7400 / @entity29321 or @entity73033 / @entity29321 . @entity73033 , @entity29321 and the @entity9158 / @entity29321 combinations produced highly significant reductions in faecal strongyle egg counts 20 days post-treatment (p less than 0.001). When administered alone, @entity9158 anthelmintics failed to reduce strongyle egg counts significantly, with the exception of @entity73033 . Larval culture and differentiation indicated that in all cases of anthelmintic failure, the species involved were small strongyles of subfamily Cyathostominae. There was no significant increase in @entity9158 resistance level (based on in vitro assay) as a result of drug treatment, over one generation.
