Anticoagulant rodenticide

Dicoumarol is found in sweet clover and can cause hemorrhaging in cattle because of its anticoagulant action. It acts as a vitamin K antagonist and has served as a model for the development of warfarin and related anticoagulant rodenticides. 

One study conducted in Britain between 1983 and 1989 was of barn owls found dead in the field 10% of the sample of 145 birds contained anticoagulant rodenticide residues in their livers, and difenacoum and brodifacoum were prominent among them (Newton et al. 1990). In another study, barn owls were fed rats that had been dosed with flocoumafen. It was found that a substantial proportion of the rodenticide ingested by owls was eliminated in pellets (Eadsforth et al. 1991). The authors suggest that exposure of owls to rodenticides in the field may be monitored by analysis of pellets dropped at roosts or regular perching places. 

Acute Oral LD50 Values for Some Anticoagulant Rodenticides... 

The anticoagulant rodenticides warfarin and superwarfarins are toxic because they have high affinity for a vitamin K binding site of hepatic microsomes (Chapter 11, Section 11.2.4). In theory, an ideal biomarker would... 

Anticoagulant rodenticides (ARs) Rodenticides that cause hemorrhaging, usually through disturbing the synthesis of clotting proteins (e.g., warfarin, brodi-facoum, difenacoum). 

Superwarfarins Second-generation anticoagulant rodenticides related to warfarin. 

Fergusson, D. (1994). The effects of 4-hydroxycoumarin Anticoagulant Rodenticides on Birds and the Development of Techniques for Non-destructively Monitoring Their Ecological Effects, Ph.D. Thesis, University of Reading, UK. 

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