Household rat poison linked to death and disease in wildlife

By Martha Groves

Los Angeles Times (MCT)

Published: Monday, April 21 2014 12:00 a.m. MDT

The most sweeping action to date was taken in March, when the state Department of Pesticide Regulation signaled plans to halt retail sales of second-generation anticoagulant rodenticides to consumers. Under the rules, slated to take effect July 1, only licensed specialists could purchase and use them.

Reckitt Benckiser Group, which makes d-CON, is seeking a preliminary injunction against the rules. The company said the “new regulation will unnecessarily put Californians at an increased public health risk from rodent infestation and place a greater financial burden on families and individuals who cannot afford professional pest control services.”

Second-generation rodenticides are dangerous even when animals ingest them in sublethal doses. The anticoagulant makes them lethargic, wildlife experts say, so they are more likely to die from exposure or be hit by cars.

The activism and regulation have centered around second-generation poisons, but older first-generation poisons also remain of concern. Those poisons were commonly used decades ago until many rodents developed an immunity. But first-generation poison can still be harmful to wildlife.

Mange is caused by a microscopic mite that burrows into the skin and causes itchiness and skin lesions. The afflicted animal loses fluids and nutrients through the skin. Complications including infection, starvation and hypothermia eventually lead to death.

The connection between exposure to anticoagulant rodenticide and mange is not fully understood, said Seth Riley, a wildlife ecologist with the Santa Monica Mountains National Recreation Area.

Mange in wild cats is rare. A decade ago, researchers documented two mountain lion deaths in the Simi Hills that they blamed on poisoning by anticoagulant rodenticides. Both had mange.

Scientists said P-22’s condition does not appear to pose a safety threat to human beings. He continues to spend most of his time in the park’s most remote areas, said Jeff Sikich, a National Park Service biologist who has tracked P-22’s activity. Shortly before he was recaptured, P-22 had killed an adult buck.

Not long ago, however, he was caught on video padding through a Hollywood Hills neighborhood. Sikich said such behavior is typical of younger male mountain lions testing their boundaries.

As for P-22’s future, “the worst outcome would be that the treatment might not work and he could continue to get sicker with the mange and eventually die from it,” Riley said. The cougar could also die directly from the anticoagulant poisoning.

And if those don’t get him? At age 4 1/2 or so, P-22 will sooner or later want to mate, and that will mean venturing out of the park.

“He’ll have a dangerous time trying to cross roads or freeways or might end up in someone’s garage or backyard,” Riley said. “Fortunately, knock on wood, he’s never behaved aggressively toward people at all. (But) you just never know in those situations.”

©2014 Los Angeles Times. Visit the Los Angeles Times at www.latimes.com Distributed by MCT Information Services

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