Protecting Wildlife from Rodenticides

Walk into any hardware store in the United States and chances are good that you can find highly toxic rodent poisons for sale. This includes loose poison pellets in open trays, not contained in any kind of bait station that would prevent non-target animals and people—particularly children—from accidentally consuming the product. A majority of rodent poisons sold in this country are first-generation (multiple dose) or second-generation (single dose) anticoagulants, which interfere with blood clotting and cause a slow death or illness from excessive internal and external bleeding.

Second-generation anticoagulants are more lethal than first-generation, and the risk to non-target animals is higher. Because they kill slowly—over 5 to 7 days—rodents keep eating the bait long after they’ve consumed a lethal dose. By the time these rodents die they have eaten many times the lethal dose and their carcasses offer a potentially deadly meal to unsuspecting predators and companion animals.

According to the Center for Disease Control and Prevention, it receives about 15,000 calls each year from parents whose children have consumed rodenticides. Due to the risk to children, pets, and non-target wildlife, a few years ago EPA changed its safety requirements for rodenticides. Products designed for sale to the public must either be less-deadly, first-generation anticoagulants or not be anticoagulants. In addition, each product must include a bait station, and loose poison baits such as pellets are prohibited. Consumers can still find these types of rodent poisons for sale, however, because stores have huge inventories of the products, and also because not all rodenticide manufacturers have complied with the new EPA standards.

In 2013, Reckitt Benckiser Inc., maker of the popular D-Con brand of mouse and rat poisons, announced that it did not intend to comply with EPA’s notice of intent to cancel 12 of the company’s products. All of the products in question are sold without a protective bait station, and 8 of the 12 products contain second-generation anticoagulants. EPA indicated this was the first time in more than 20 years that a manufacturer declined to voluntarily implement EPA safety standards. On May 30, 2014, after more than a year of negotiations, EPA announced an agreement with Reckitt in which the company will cease production of these products by the end of this year.

Few states have looked at how rodenticides affect non-target wild animals. One that has is California, which reports extremely alarming statistics regarding the presence of rodenticides in wildlife. For example, research supported by AWI’s Christine Stevens Wildlife Award program has helped demonstrate a connection between an outbreak of severe mange in California bobcats and ingestion of rodenticides, which increases an animal’s susceptibility to the disease. In addition to bobcats, the products can cause illness and death among golden eagles, coyotes, foxes, mountain lions, and other predators that consume rodent poisons, either directly through eating the poison bait or secondarily through eating the carcass of a rodent who consumed the bait.

Citing the threat to pets and wildlife, California legislators this year banned the retail sale of anticoagulant poisons, effective July 1, 2014. Unfortunately, anticoagulant poisons, both first- and second-generation, can still be used by commercial animal control operators in the state. And while progress is being made to protect predators and scavenging wildlife from direct and secondary poisoning, nothing is being done to reduce the severe suffering inflicted by slow-acting poisons on the intended target—rats and mice.