Bill Seeks to Expand Ban on Rodenticides

P-53 is the latest victim of a deadly rodenticide-related mange infection. Nearly all of the animals in the National Park Service study of the big cats in the Santa Monica Mountains show evidence of rodenticide exposure—many have traces of more than one anticoagulant rodenticide in their blood. Some mountain lions have “bled out,” dying from internal bleeding, the primary cause of death from the poison. It is more common for the rodenticide to weaken the animal’s immune system, leaving them susceptible to mange, a potentially life threatening parasitic infection. P-53 was captured and treated. She may survive. Other animals haven’t had that chance. Bobcats and coyotes are also afflicted and frequently die. Photos courtesy National Park Service

Just days before California Assemblymember Richard Bloom (D-50) submitted a new bill seeking to extend protections for wildlife from deadly anticoagulant rodenticides, this type of rat poison nearly claimed another high-profile victim.

Mountain lion P-53 became the fifth animal in the National Park Service’s study of the big cats in the Santa Monica Mountains to be diagnosed with rodenticide-linked mange.

“It’s concerning to see this mange in a mountain lion, because it generally means that the animal is compromised in some other way such as having been exposed to toxicants,” said Seth Riley, wildlife ecologist for Santa Monica Mountains National Recreation Area and adjunct associate professor at UCLA. “We are hopeful the treatment will be successful and that we can monitor P-53’s recovery through remote camera images.”

In July 2014, the California Department of Pesticide Regulation prohibited the sale of second generation anticoagulant rat poison to consumers, but stopped short of banning commercial pest control companies from using the chemicals.

“Most of the poison is actually supplied by commercial pest control companies that service residents and businesses,” wrote Poison Free Malibu co-founder Kian Schulman in a statement on the new assembly bill. “Four years later, the data have indeed shown no decrease in the rate of poisoning of wildlife. Our bill is meant to include the pest control companies in the ban so that they also cannot use second generation anticoagulants.”

Schulman explained that first generation anticoagulants, only slightly less devastating than the second generation, will be banned from certain state and local parks and wildlife areas, as well.

Los Angeles County included a ban on anticoagulant rodenticides in its Local Coastal Plan for the unincorporated area of the Santa Monica Mountains in 2014, arguing that the Coastal Act gives the Coastal Commission the authority to enforce the ban, but other areas, including the City of Malibu, have balked at a local ban, arguing that the mandate must come from Sacramento.

The new bill comes on the heels of a new state analysis that has documented the presence of anticoagulant rat poisons in more than 85 percent of tested mountain lions, bobcats, and Pacific fishers, an endangered member of the weasel and otter family.

Anticoagulants prevent blood from clotting, causing rodents, or any animal that ingests the poison, to bleed to death internally. It’s a slow death.

At least two mountain lions in the Santa Monica Mountains have bled to death directly from consumption of animals poisoned with anticoagulants. It appears to be more common for apex predators like bobcats and mountain lions to develop weakened immune systems that can lead to death from mange, a parasitic infection.

P-53 was reportedly nearly blind from the mange when she was picked up by researchers and treated. P-22, the Griffith Park mountain lion who has become the poster cat for urban wildlife, was successfully treated for the same condition in 2016 and recovered. Riley hopes that his team intervened in time to save P-53.

The recent California Department of Pesticide Regulation analysis of 11 different wildlife studies indicates non-target animals continue to be poisoned in large numbers despite state restrictions on the sale and use of the deadliest rodenticides put in place in 2014. “The long-lasting super toxins often poison non-target animals that eat poisoned rodents,” the report found.

“This alarming new evidence should spur the state to ban these dangerous poisons,” said Jonathan Evans, legal director of the Center for Biological Diversity’s environmental health program. “There are safer, cheaper alternatives that greatly reduce risks to wildlife, pets, and children. Pesticide regulators have no excuse for continuing to allow California’s wildlife to die slow, excruciating deaths.”

AB 1788 would expand the prohibition to the entire state. However, agricultural activities would be exempt, and there is another major loophole: the bill would “authorize the use of a pesticide containing a specified anticoagulant” if the State Department of Public Health determines that there is a public health emergency due to a pest infestation and the various regulatory agencies concur that the emergency warrants the use.

Advocates say that even with the exemptions, the bill would help to greatly reduce the availability of anticoagulants, which are currently used in the ubiquitous black plastic bait boxes deployed around commercial and residential buildings, even in the Santas Monica Mountains, despite the local ban. Whether it passes or fails, the bill also raises awareness of the rodenticide crisis impacting almost all wildlife in the state and across the nation.


To learn more, and to track the bill as it makes its way through the assembly committees: or Richard Bloom’s official website:


Suzanne Guldimann

Suzanne Guldimann is an author, artist, and musician who lives in Malibu and loves the Santa Monica Mountains. She has worked as a journalist reporting on local news and issues for more than a decade, and is the author of nine books of music for the harp. Suzanne's newest book, "Life in Malibu", explores local history and nature. She can be reached at

No Comments Yet

Leave a Reply

Your email address will not be published.