Ask the Vet

A Better Mousetrap

Concerns about one type of rat poison may make the time-proven barn cat a better choice for rat and mouse control. (DTN/Progressive Farmer photo by iStock/Thinkstock)

Question: We have to keep rat poison out in our barns all the time. I have heard there is a type of rat poison that is very dangerous to dogs and cats. Is this true?

Answer: Unfortunately, this is absolutely true. The EPA has put restrictions on some rodenticides, including anticoagulant-types. In fairness these products do cause significant numbers of poisonings and death in wildlife and other non-target species, including fox and raptors, which are predators of the rats and mice we want to control.

Rodenticides are slow acting because of the feeding habits of rats and mice. Rodents will eat a small amount and wait to see if they get sick before eating more. These animals, sometimes weakened by the poison, are then eaten by wildlife who are then poisoned and may die themselves.

But the "solution" may be worse than the problem. Bromethalin, a rodenticide on the market since the mid-1980s, had, in many cases, replaced super warfarins as the active ingredient. In several cases, companies use the same name and packaging, adding no warnings regarding the change in active ingredients. When pets are accidently poisoned by super warfarin, veterinarians have a clear set of signs, diagnostic tests and a safe, economical and effective antidote that prevents or reverses the toxic effects.

Unfortunately with Bromethalin, there is no diagnostic test, and there is no antidote. Signs of ingestion include loss of appetite, wobbly gait, paralysis beginning with the hind limbs, slight muscle tremors, generalized seizures and depression. Higher doses may cause sudden onset of severe muscle tremors, seizures and death. This is a case of the solution being worse than the problem.

I recommend you read the label on any poison you have and know what you are using. Tear out this page, and post it where you can quickly see the signs of accidental poisoning I mentioned. Always use bait stations, placed in areas where children and pets do not have access. Clean up the environment, removing areas where rodents may hide. Store feed so rodents can't get to it.

Lastly, don't forget our old friend the barn cat. If you're looking for a natural way to keep the rats and mice out, a better mousetrap has never been invented. A good "mouser" can truly be worth his weight in gold.