Dear Christopher Cat
Our mouse problem is particularly bad this winter, despite the fact that our cats are good mousers. Is it safe to put out mouse poison?
I, too, am an excellent mouser, but just this morning, Mom dug into a bag of bird seed and scooped out a dead mouse. Oops, I guess I missed one.
What you are pondering, whether a cat can be poisoned by eating a mouse that ingested poison, is called relay toxicosis. It occurs when a mouse eats a large enough dose of poison, and the cat eats the entire mouse.
The toxic dose depends on the poison. The three most common poison types are:
1) vitamin D3 (cholecalciferol), which increases calcium to deadly levels and is found in products like Quintox and Rampage;
2) an anticoagulant, which causes internal bleeding; common names are warfarin, brodifacoum and bromadoline; and
3) bromethalin, which damages the brain and is found in products like Vengeance and Assault.
The ASPCA Animal Poison Control Center recommends emergency treatment if a 10-pound cat eats a mouse that consumed as little as 0.02 ounce of a vitamin D3 bait, 0.06 ounce of an anticoagulant bait or 0.12 ounce of a bromethalin bait.
So here’s my advice: plug the holes in the house, put the bird seed in a metal tin and keep the mouse poison out of the house.