Whole‐carcass residues of the rodenticide difenacoum in anticoagulant‐resistant and ‐susceptible rat strains (Rattus norvegicus)

Abstract

The present study investigated the whole-carcass residue carried by resistant and susceptible laboratory rat strains following 5, 10, or 20 d of feeding on a diet of 25 mg difenacoum/kg bait. The mean whole-carcass residue of difenacoum was determined by high-performance liquid chromatography to be between 0.52 and 0.74 mg/kg body weight in all three rat strains tested. These values were considerably lower than some comparable data previously reported for other species and second-generation rodenticides as well as from mathematical models. The whole-carcass residue of extractable (i.e., nonrefractory) parent compound carried by highly resistant rats fed for 20 d (0.74 mg/kg body wt) is unlikely to present a significantly increased risk to predators compared to the amount carried by susceptible rats after 5 d of feeding (0.52 mg/kg body wt). However, resistant rats are more likely to be available for predation and to be carrying a whole-carcass residue of anticoagulant throughout the duration of a control program.

Development of an Ecofriendly Anticoagulant Rodenticide Based on the Stereochemistry of Difenacoum

“…It is efficient to control warfarin-resistant rodent populations , (Hadler and Shadbolt, 1975), (RRAC, 2015) and would be less toxic for non-target species than for target species (Buckle and Smith eds, 2015). This molecule is widely used worldwide (Buckle et al, 2013), (Atterby et al, 2005), (Hughes et al, 2013). For example difenacoum was reported to be used on approximatively 45% of agricultural premises in Great Britain (Buckle et al, 2013), (Atterby et al, 2005).…”

“…This molecule is widely used worldwide (Buckle et al, 2013), (Atterby et al, 2005), (Hughes et al, 2013). For example difenacoum was reported to be used on approximatively 45% of agricultural premises in Great Britain (Buckle et al, 2013), (Atterby et al, 2005). It is used to control rodent pests in and around buildings, in waste sites and in sewers (European Parliament, 2009) but, according to the European countries, not always authorized in open areas because of its associated ecotoxicity.…”

Hazards of Secondary Bromadiolone Intoxications Evaluated using High-performance Liquid Chromatography with Electrochemical Detection

“…Due to this the occurrence of bromadiolone can be very expected in tissues of many predators although the respective concentration may not always result in toxic effects [16]. Close attention is being devoted to the occurrence of residues in the environment, with pesticide-derived compounds representing an important group of residues [68]. Moreover earthworms are useful bioindicators of agroecosystem polluting [69].…”

Elevated difenacoum metabolism is involved in the difenacoum‐resistant phenotype observed in Berkshire rats homozygous for the L120Q mutation in the vitamin K epoxide reductase complex subunit 1 (Vkorc1) gene

“…Difenacoum was the first SGAR available on the market . It is now used widely throughout the world . Its use is permitted throughout Europe to control populations of rats and mice in and around buildings, in waste sites and in sewers, and, depending on the country, in open areas.…”

“…1,2 It is now used widely throughout the world. 15,19,20 Its use is permitted throughout Europe to control populations of rats and mice in and around buildings, in waste sites and in sewers, and, depending on the country, in open areas. For example, difenacoum was reported to be used in approximately 45% of agricultural premises in Great Britain.…”