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An analysis of the susceptibilities of several populations of Rattus norvegicus to warfarin

  • Joe E. Brooks (a1) and Alan M. Bowerman (a1)

Summary

An analysis was made of the dose-response of several populations of Rattus norvegicus fed upon baits containing 0·005% warfarin for various numbers of days. Warfarin-susceptible populations fell within a narrow range, with LFP50s and LFP98s (lethal feeding periods in days to obtain 50% and 98% mortalities respectively) of up to 3·0 and 5·0 days respectively. The probability of an individual rat from these populations surviving a six-day feeding period was estimated at 0·003 or less. Populations with responses falling beyond these limits were regarded as warfarin-resistant.

Six of nine populations of R. norvegicus, from England, Germany and the United States, were determined to be warfarin-susceptible within the narrow limits given above. In all six cases, no animals survived the six-day WHO feeding test for anticoagulant susceptibility. In three populations from the United States, where rats survived six days feeding, their population responses clearly fell outside the measures given above. It is suggested, tentatively, that anticoagulantresistant Norway rat populations be defined as those whose LFP50 and LFP98 exceeds 3·0 and 5·0 days respectively, and in which the probability of an individual animal surviving a six-day feeding upon 0·005% warfarin is 0·01 or more.

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Copyright

References

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Bentley, E. W. (1969). The warfarin resistance problem in England and Wales. Schriftenreihe des Vereins für Wasser., Boden- und Lufthygiene 32, 1925.
Brooks, J. E. & Bowerman, A. M. (1973). Anticoagulant resistance in wild Norway rats in New York. Journal of Hygiene 71, 217–22.
Drummond, D. C. (1966). Tentative instructions for determining the susceptibility of rodents to anticoagulant rodenticides. World Health Organization, Seminar on Rodents and Rodent Ectoparasites 66.217, 139–48.
Drummond, D. C. & Wilson, E. J. (1968). Laboratory investigation of resistance to warfarin of Rattus norvegicus Berk. in Montgomeryshire and Shropshire. Annals of Applied Biology 61, 303–12.
Jackson, W. B., Brooks, J. E., Bowerman, A. M. & Kaukeinen, D. E. (1973). Anticoagulant resistance in Norway rats in U.S. cities. Pest Control 41 (4), 56, 81.
Litchfield, J. T. Jr. & Wilcoxon, F. (1949). A simplified method of evaluating dose–effect experiments. Journal of Pharmacology and Experimental Therapeutics 96, 99113.
Rowe, F. P. & Redfern, R. (1964). The toxicity of 0·025% warfarin to wild house mice (Mus musculus L.). Journal of Hygiene 62, 389–93.
Telle, H. J. (1971). Resistance to warfarin of the Brown rat (R. norvegicus) in Germany. World Health Organization, VBC/71.331, 5 pp. (Unpublished working paper.)
World Health Organization (1970). Provisional instructions for determining the susceptibility of rodents to anticoagulant rodenticides. World Health Organization, Technical Report Series, no. 443, pp. 140–7.

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