Register of anthelmintic resistant nematodes in New Zealand

Abstract Extract Sir:- Since the first report of anthelmintic resistance in N .Z. in 1979(9) many new cases have been found. Published instances of resistance, together with some other cases investigated by us, are summarised in Table I. In addition, but not tabulated, there are numerous unsubstantiated reports of resistance (i.e. reduced efficacy of drenches, apparently not related to drenching procedures) as well as a number of confirmed but unpublished records.