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Anticoagulant Rodenticide Toxicity (view source)
Revision as of 13:03, 23 August 2010
, 13:03, 23 August 2010→Description
==Description==
==Description==
Anticoagulant rodenticides were first discovered during ingvestigations into mouldy sweet clover poisoning in cattle<sup>1</sup>. In this condition, naturally occuring coumarin in clover is converted by fungi to a toxic agent, dicumarol, which causes a haemorrhagic syndrome when ingested. Initially, warfarin was synthesised and used in this way for rodent control, but as rodents have developed a resistance to the substance new, second-generation anticoagulant rodenticides have been developed. These include difenacoum, bromadiolone, coumafuryl and brodifacoum amongst others, which may all causes toxicity in animals in the same way as warfarin.
Anticoagulant rodenticides were first discovered during ingvestigations into mouldy sweet clover poisoning in cattle<sup>1</sup>. In this condition, naturally occuring coumarin in clover is converted by fungi to a toxic agent, dicumarol, which causes a haemorrhagic syndrome when ingested. Initially, warfarin was synthesised and used in this way for rodent control, but as rodents have developed a resistance to the substance new, second generation anticoagulant rodenticides have been developed. These include coumarin (bromadiolone and brodifacoum) and indandione (pindone and diaphacinone) rodenticides, which along with warfarin may cause toxicity following accidental ingestion in animals.
Anticoagulant rodenticide toxiticy is one of the most common causes of acquired coagulopathy in small animals. Warfarin itself has a short half-life and a fairly low toxicity in non-rodent species, so unless large or repeated doses are consumed clinical bleeding is rare. However, the second generation anticoagulant rodenticides are far more potent, with tendency to accumulate in the liver and a long half life (4-6 days) owing to high levels of plasma protein binding<sup>2</sup>. This means it is possible for a domestic animal to acquire secondary poisoning by ingesting a killed rodent.
The coumarin derivatives exert interaction of
The coumarin derivatives exert interaction of
their anticoagulant eftect by inhibiting the enzyme, vitamin K epoxide reductase (see box on page 63). This enizymiie is a component of
their anticoagulant eftect by inhibiting the enzyme, vitamin K epoxide reductase (see box on page 63). This enizymiie is a component of