Rats have been around us for centuries, and for centuries, we’ve tried to push them away. One of the ways in which we tried to do this was through poisoning, which is a fairly old control method.

Today, rat poisons are fairly bening, compared to the poisons that we used to employ before the 1940s, when rodenticides were filled with heavy metals such as thallium and arsenic, or poisons such as red squill and others. Most of these chemicals have been phased out today, because they were quite dangerous, and instead, we use rodenticides known as anticoagulants. Anticoagulants work by disrupting the clotting process so that the poisoned rats suffer from uncontrolled hemorrhaging. We also have non-anticoagulant rodenticides at our disposal, which we will get into later.

Anticoagulant rodenticides

Anticoagulants can be divided into first generation and second generation. The first generation anticoagulants will only reach a lethal dosage after they have been consumed in several consecutive feedings, and they include chlorophacinone, diphacinone, and warfarin. The danger with using rodenticides in general is that they can lead to primary or secondary poisoning.

Primary poisoning occurs when an organism that is not the targeted pest consumes the rodenticides, and secondary poisoning occurs when an organism consumes the poisoned rodent. Different rodenticides will have different risks of primary and secondary poisoning. For first generation anticoagulants, the risk of primary poisoning is low to moderate, with warfarin being highly toxic to cats, and the secondary poisoning risk is low, moderate or high depending on the rodenticide and the organism that consumes the poisoned rodent. For example, chlorophacinone presents a low risk of secondary poisoning to birds, but a high risk to mammals, while warfarin is moderate across the board.

Second generation anticoagulants are much more poisonous than the first generation compounds, with one feeding delivering a lethal dose. These rodenticides include brodifacoum, bromadiolone and difethialone among others. Naturally, these anticoagulants present a much higher primary and secondary poisoning risk.

Non-anticoagulant rodenticides

These rodenticides are much more varied than the previous two categories, both in their effects and potency. However, what is interesting is that most of them have low to moderate primary and secondary poisoning potential, with some, such as cholecalciferol, being completely harmless in small quantities. Cholecalciferol is a biologically active form of vitamin D which is only toxic in either massive doses, or in prolonged exposure to low level doses.

Finding the right poison

Using poisons is sometimes frowned upon, because you do not know where the rats will die. They may die out in the open, or they may die somewhere in your walls or in a hard to reach area. This is why it’s best to leave rat poisoning and trapping to the professionals. Contact us today if you have rat infestation and you would like to get rid of it.