Fiery emails show EPA turmoil over pet collars tied to deaths

By E.A. Crunden | 03/25/2022 01:39 PM EDT

A trove of internal emails show EPA managers have sought to downplay qualms from agency scientists over the safety of flea collars linked to nearly 1,700 animal deaths and 75,000 incidents of animal harm.

Seresto pet collars are offered for sale at a retail store in Chicago.

Seresto pet collars are offered for sale at a retail store in Chicago. According to EPA documents, the flea and tick collars have been linked to hundreds of pet deaths and tens of thousands of pet injuries. Scott Olson/Getty Images

EPA career scientists raised concerns about pesticide-laced collars linked to pet deaths, but agency managers instructed them to avoid documenting those worries in publicly accessible records, according to internal emails.

Released through a Freedom of Information Act lawsuit filed by the Center for Biological Diversity, a trove of internal emails show EPA managers have sought to downplay qualms from agency scientists over the safety of flea collars linked to thousands of animal deaths. In particular, they worried about Seresto collars, approved by EPA nearly a decade ago but connected to nearly 1,700 animal deaths and 75,000 incidents of animal harm.

EPA has been vague in its response to pushback over the product, saying publicly that it is in conversations with Elanco Animal Health Inc. to better understand the product. But internal communications show a very different understanding of the risks posed by the collars.


In one exchange released under FOIA, a member of the California Department of Fish and Wildlife reached out to EPA following an investigation by the Midwest Center for Investigative Reporting that first raised concerns about the collars. The state has been using the product on endangered San Joaquin kit foxes. In emails discussing the situation, EPA staff expressed dismay.

“Why is Seresto even registered?” asked one staffer. “At the very least Seresto should not be used on the endangered San [Joaquin] Kit Fox.”

A manager responded, telling the staffer “it would be inappropriate for you to respond in your official capacity and express your personal opinions.” The staffer fired back and noted that manager had been part of efforts telling staff “not to express our concerns about Seresto in emails.”

Other emails unearthed through the lawsuit show similar concerns and dynamics between scientists and EPA managers. In one exchange, a staffer wrote “I hope this time someone can blow the lid off this travesty” in response to media articles looking closely at the issue, while lamenting Seresto’s high scores on

The Center for Biological Diversity sued for communications concerning the pet collars a year ago, after waiting on documents since August 2020 (Greenwire, April 14, 2021). In response to the released emails, Lori Ann Burd, the center’s environmental health director, labeled the exchanges “disturbing” and raised questions about “the agency’s transparency and scientific integrity” in light of the revelations.

“You’d think the EPA would spring to action in response to these troubling reports,” Burd said. “But these emails tell the story of an agency focused more on saving face than saving animals.”

An EPA spokesperson said the agency “looked into these staff communications and concluded that no direction was given to staff to not express their opinion in email to avoid public disclosure.”

Via email, the spokesperson said EPA “understands and shares the public’s concerns” about the pet collars and noted officials sought information from Elanco last year about Seresto. EPA has also requested support from the Food and Drug Administration on the review, a conversation that remains ongoing.

The agency will use the information it has collected “to determine whether the continued registration of these pet collars still meets the legally required standard of no unreasonable adverse effects on the environment, taking into account the economic, social, and environmental costs and benefits of the use of the pesticide.”

EPA also asked for public comment on a petition from CBD to cancel Seresto’s registration. The comment period ended in September, and the agency will respond to the petition after reviewing its evaluation.

Concerns about the Seresto collars, as well as similar products, have been ongoing for many years.

Seresto contains two pesticides, imidacloprid and flumethrin, and the implications of their combined impacts have not been well explored. Environmental and health groups maintain they create a cocktail that poses dangers to animals and to people.

Beyond Seresto, the Natural Resources Defense Council has fought EPA over tetrachlorvinphos, or TCVP, a pesticide used in collars sold by Hartz Mountain Corp. NRDC has repeatedly challenged EPA in court over those collars, resulting in a 2020 order from a federal court demanding the agency make a decision about the product (E&E News PM, April 22, 2020). Under the Trump administration, however, EPA opted to deny NRDC’s petition, leading to another lawsuit.

Lawmakers have also scrutinized issues with pet collars. Last March, House Oversight and Reform Subcommittee on Economic and Consumer Policy Chair Raja Krishnamoorthi (D-Ill.) requested documents and information on Seresto collars from its manufacturers (Greenwire, March 19, 2021). At the time, Elanco firmly stood behind the product, asserting that press coverage had been “based on raw data and cannot be used to draw conclusions” about the safety of the collars.

The back and forth is likely to remain heated with the release of the internal EPA emails, raising more fears about the risk to animals.

“The heartbreaking tragedy is that behind each and every incident report is a story of very real pet suffering, from violent seizures, rashes and hair loss to gastrointestinal problems and even deaths,” said Burd.