The most common forms of mouse and rat poison contain products that make it impossible to clot blood. These so-called anticoagulant rodenticides are seriously poisonous to cats and dogs. Pets that ingest anticoagulant rodenticides will be symptom-free for several days, but then will start to suffer from bleeding that can be fatal. Very small quantities of the most modern poisons are sufficient to kill a pet. Click the link above for more information.
This leads to a question. Say a mouse consumes anticoagulant rodenticide. After a few days it will become weak and lethargic–and therefore much less likely to escape from a hunting house cat. If the cat catches and consumes the mouse, will the poison in the mouse’s system affect the cat?
This phenomenon is called secondary intoxication. It is a big concern in theory. Fortunately, in practice it appears to be a rare event.
There is little doubt that if a mouse’s stomach is full of poison when a cat consumes it then the cat will be poisoned. However, poison in a mouse’s blood stream does not appear in practice to harm cats very often.
Nonetheless, as I mentioned above, anticoagulant rodenticides are very serious business. Any cat or dog who may possibly have been exposed to such poisons in any way–including by secondary intoxication–should be seen by a vet. Blood clotting tests run at appropriate times can detect the poison in pets’ systems. Fortunately, there is an antidote to the poisons: vitamin K.
I strongly recommend that cat and dog owners not stock or use any forms of mouse or rat poison. The risks to pets are simply too great.
Photo: Arwen is not likely to be poisoned by this mouse.