Data on resistance of residential grey rats to 2nd generation anticoagulants

The chemical method of deratisation is the main means of regulating the numbers of synanthropic rodents. Low efficiency of deratisation measures can be related both to resistance of rats and mice to blood anticoagulants and to low attractiveness of baits. Thus, low eatability of baits entails insufficient cumulation of poison and, as a consequence, insufficient toxic effect on the animal organism. This paper describes the results of experiments to study the degree of sensitivity of grey rat individuals to the second generation anticoagulants bromadiolone and brodifacoum, most commonly used in deratisation practice. Sensitivity was determined by direct injection of anticoagulant solutions in neutral solvent into the stomach. The mean lethal concentration calculated by Hill’s equation for a single gastric administration was 0.35 mg/kg for bromadialone and 0.182 mg/kg for brodifacoum. The data obtained can be used in calculating the required amount of bait that must be eaten by the rodent to achieve lethality. Keywords: synanthropic rodents, grey rat, deratisation measures, anticoagulants, bromadiolone, brodifacoum.