ANTICOAGULANT RODENTICIDES

    

Nobody wants rodents in their house or yard, but commonly used poisons to control them do significant damage to the environment and your family’s health.

Starting July 1, California has banned consumer use of these poisons, which are spreading throughout the ecosystem causing massive exposure, disease, and death beyond the intended rodent targets. Scientific studies tell us that rodent poisons are a leading cause of death among carnivores, and also endanger our children and pets. Ninety percent of coyotes, bobcats, hawks, owls, and mountain lions are affected, and the ban represents a huge advance in safety in the environment and around the home.

The banned products can be identified by their active ingredients: Brodifacoum, Bromadiolone, Difenacoum, and Difethialone. Exterminators and pest control companies will still be allowed to use these poisons. For more information about the ban, please visit www.cdpr.ca.gov/docs/legbills/rulepkgs/13-002/13-002.htm. To learn more about the damage these poisons do to wildlife, please visit www.cdpr.ca.gov/docs/registration/reevaluation/chemicals/brodifacoum_final_assess.pdf.

 

 

Information on the Effects of Rodenticides on Wildlife

The Calabasas City Council adopted Resolution No. 2013-1379 urging businesses in Calabasas to no longer sell or use anticoagulant rodenticides, urging all property owners to cease purchasing or using anticoagulant rodenticides on their properties in Calabasas and committing the City of Calabasas to not use anticoagulant rodenticides as part of its maintenance program for city-owned parks and facilities.

 

Rodenticides can harm wildlife; please use carefully

Throughout California, the use of poison baits, or anticoagulant rodenticides, to control rodents has injured and killed numerous wild animals and pets. This is because predatory and scavenging birds and mammals like owls, hawks, raccoons, foxes, skunks and coyotes eat dead or dying rodents that have consumed these baits and will, therefor, also be poisoned. Pets may also eat infected dead or dying rodents and unprotected bait and become poisoned.

You can protect both pets and wildlife by reading – and following – the label directions of any rodent baits you purchase and only purchasing those that are legal for the pest you are trying to control. Non-chemical means of rodent control, such as exclusion and sanitation, should be used when possible to prevent rodenticide exposure to non-target wildlife and pets. Because of documented hazards to wildlife, pets, and children, the U.S. Environmental Protection Agency is in the process of canceling products that do not comply with safety requirements (see www.epa.gov/pesticides/mice-and-rats).

Protect your wild neighbors and pets from accidental poisoning. Use all pesticides very carefully and follow all label directions, or instead, choose non-chemical pest control methods.

 

Frequently-Asked Questions

Q. How do rodent baits harm wildlife and pets?

A. It's possible for wildlife and pets to consume the poison directly. However, it's more common for some animals to be affected by a secondary exposure. A secondary exposure occurs when wildlife or pets consume dead or dying rodents that have eaten the poisons. Wildlife that can be affected by secondary poisoning include owls, hawks, eagles and mammals such as raccoons, foxes, bobcats, mountain lions and coyotes.

Q. How can I protect wildlife and pets, but still control rodent pests?

A. The most effective and safest ways to address rodent issues are through exclusion and sanitation. For example, seal off entrances to your home, remove debris from your yard, and make pet food inaccessible to rodents. Traps can also be effective in removing rodent pests. If you use rodent bait, it is important to follow label directions carefully. Rodent baits with the active ingredients brodifacoum, bromadiolone, difethialone, and difenacoum are very toxic and persistent and have been found widely in non-target wildlife due to secondary consumption.

  • Read product labels carefully before using any pesticide, and follow directions exactly. Check for the harmful active ingredients mentioned above.

  • Check daily for dead rodents. Wearing gloves, collect the carcasses as soon as possible, place in plastic bags and dispose in garbage cans with tight lids that other animals can't open. Always wear protective gloves when handling any dead animal.

Q. What kind of rodenticides should I NOT use in the yard, away from buildings?

A. You should not use over-the-counter rodenticides, such as d-Con®, that contain the active ingredients brodifacoum, bromadiolone, difenacoum or difethialone. These can only be legally used to control rats and house mice in and around structures. It is illegal to use these products in open areas such as pastures or fields. Products containing bromethalin and cholecalciferol may also not be used for field rodent control.

Q. Why is brodifacoum so dangerous for wildlife and pets?

A. Brodifacoum, bromodialone, difenacoum and difethialone are toxic to rodents in a single feeding. However, the rodent will not die until several days after feeding and may continue to ingest more poison. The poison is then available to a predator or scavenger that eats the rodent within those several days of intoxication. If the exposed rodent does not die, the poison can persist in its body for several months and can therefor be exposed to wildlife and pets for those several months.

Q. How do these rodent baits work?

A. Brodifacoum, bromodialone, difenacoum and difethialone are second-generation anticoagulants. Warfarin, chlorophacinone, and diphacinone are first generation anticoagulant rodenticides. Both types of anticoagulant rodenticides work by disrupting blood clotting. Animals that ingest them die from internal hemorrhaging (bleeding) several days after ingesting the material. While the mechanism of all anticoagulants is similar, second-generation products (brodifacoum, bromadiolone, difenacoum and difethialone) are much more toxic and persistent and pose a much bigger threat to non-target wildlife. Cholecalciferol is an acute rodenticide which causes hypercalcemia. Bromethalin is an acute neural toxicant.

Q. How do you know rodent baits are poisoning wildlife?

A. Since 1994, CDFW's Wildlife Investigation Laboratory has confirmed at least 300 cases of wildlife poisoning from anticoagulant rodent baits. Brodifacoum was the poison most frequently detected. Animals harmed include the coyote, gray fox, San Joaquin kit fox, raccoon, fox squirrel, bobcat, red fox, gray fox, mountain lion, black bear, Hermann's kangaroo rat, bald eagle, golden eagle, Canada goose, great-horned owl, barn owl, red-shouldered hawk, red-tailed hawk, Cooper's hawk, turkey vulture and wild turkey.

Since animals typically retreat to their dens, burrows or other hiding places in the final stages of anticoagulant rodenticide poisoning, the number of non-target wildlife killed by these compounds is likely to be much greater than we know. Field monitoring of wild populations of bobcats, mountain lions, coyotes, San Joaquin kit foxes, fishers, and raptors confirm widespread poison exposure to predatory and scavenging wildlife.

Q. Can I control rodent pests without using poison baits?

A. The most effective rodent control program uses exclusion techniques (such as sealing entrances to your home) and sanitation (removing rodent habitat such as ivy or wood piles); animal removal is used only when necessary. More information on controlling mice, rats, and field rodents is provided on the University of California Integrated Pest Management Website.

Q. If I think my pet has been poisoned, what should I do?

A. If your pet is having seizures, is unconscious or losing consciousness, or is having difficulty breathing, phone ahead and take your pet immediately to your local veterinarian or emergency veterinary clinic. In addition, if you see your pet consuming rodenticides, call your veterinarian immediately – do not wait for symptoms. If you are aware of any rodenticide that your pet has had access to, bring this information with you as it will help the veterinarian effectively treat your pet.

 

Helpful link:

www.epa.gov/pesticides/mice-and-rats

www.dfg.ca.gov/wildlife/WIL/pesticide/challenge.html

www.theacorn.com/news/2013-09-12/Community/PROTECTING_WILDLIFE.html

www.theacorn.com/news/2006-05-25/Health_and_Wellness/057.html

www.theacorn.com/news/2012-12-06/Community/Cause_of_mountain_lions_death_a_mystery.html

www.marketplace.org/topics/sustainability/food-chain-rodenticide

 

Educational Materials:

City of Calabasas Brochure

Anticoagulant Rodenticides: Secondary Poisoning of Wildlife in California, a PowerPoint Presentation by Stella McMillin California Department of Fish and Game Wildlife Investigations Laboratory:
http://caforestpestcouncil.org/wp-content/uploads/2013/01/stella-Mcmillin.pdf

Use of Anticoagulant Rodenticides in Single-Family Neighborhoods Along an Urban-Wildland Interface in California: http://digitalcommons.lmu.edu/cgi/viewcontent.cgi?article=1100&context=cate

 

City of Calabasas © 2014