License to Kill

License to Kill

I’m certain the EPA thought they were doing everyone a favor when they elected to do away with anticoagulant rat and mouse poisons. These are compounds that inhibit normal coagulation (blood clot formation). You need your clotting system to work correctly in order to keep the blood where it belongs—inside your veins and arteries. If your pet accidentally ingests this kind of poison, it’s quite dangerous. Blood will begin to seep uncontrollably from any surface in the body, internal or external, eventually accumulating in the chest or abdominal cavity. It’s useless there, as blood has to travel through the vessels to do its job.

That type of poison is becoming harder to find these days. Now frustrated homeowners with mouse-infested garages will be more likely to pick up a bromethalin bait. Bromethalin, like its predecessor, is laced with flavoring to make it attractive to mice. Of course, that flavor and smell also acts as a lure to our pets. Pets with a smaller body weight are more easily poisoned; furthermore, cats are about ten times more sensitive to bromethalin than dogs are. Younger animals, the ones most likely to pick up and eat unfamiliar materials, are also more rapidly harmed due to their immature nervous systems. Once it’s digested, bromethalin can cause a variety of neurologic problems that rapidly become irreversible. Tremors, hyperactivity, and incoordination are usually the first deficits observed, but this syndrome can progress to paralysis, seizures, and coma. The signs of bromethalin poisoning closely mimic those of spinal or head trauma, and the situation is especially confusing since the patient may appear normal for up to two weeks after eating it.

Then there’s the issue of an antidote. Few poisons have a true antidote like in the movies, but the old style mouse poison was one of them. If anticoagulant rodent bait was the culprit, we had four or five days to initiate treatment, and the therapy was virtually foolproof. If in doubt of the diagnosis, a blood test could rapidly identify clotting dysfunction and a second test could pinpoint poison as the exact source. Bromethalin, now…there is no antidote, there is no wide-open window for treatment, and the test to identify it is called an autopsy. All that makes our job as veterinarians much more difficult.

This change was made by the EPA with the idea of protecting wildlife species and children, but it’s made the lives of our pets more dangerous. If you use rodent baits to protect your home, you need to know that the newer varieties of mouse poison are profoundly dangerous. If you are going to use this on your property, you would really be stupid to leave even a speck of it lying around where a pet (or child) could ever get to it, even by getting really creative. It’s meant to be used inside a sturdy plastic box, a bait station, that only allows access by mice. Store the excess bait in a flawlessly secure location.

Better yet, use an old-fashioned trap.

Dr. M.S. Regan