Send to

Choose Destination
See comment in PubMed Commons below
Vet Rec. 2002 Aug 10;151(6):165-9.

Sustainable use of anthelmintics in grazing animals.

Author information

Department of Clinical Veterinary Science, University of Bristol.


It is suggested that the major factor in avoiding the development of anthelmintic resistance is the percentage of worms that do not encounter the anthelmintics (worms in refugia). This in turn is determined by the numbers of larvae on pasture, the percentage of animals treated and whether any stages in the host can avoid the action of anthelmintic. To maintain anthelmintic efficacy the percentage of worms in refugia must be sufficiently large. In cattle, this should involve treating only first-year animals and using a different pasture each year for calves. For sheep, only animals that have to be treated should be dosed with anthelmintic and clean grazing strategies that involve the use of anthelmintics should be avoided. For horses, reliance should be placed on the removal of faeces from pasture and only treating when the animals' condition requires it. Without a change in anthelmintic use there is the likelihood of increasing numbers of cases for which no anthelmintic is effective and animal welfare may be compromised.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons


    Supplemental Content

    Loading ...
    Support Center