Maker of Seresto defends flea-and-tick collar amid calls for a ban over safety concerns
The company behind the popular Seresto flea-and-tick collar filed a lengthy defense of the safety of its product amid calls for federal regulators to ban it over concerns of harm and death to the pets who wear it.
In a public comment to the Environmental Protection Agency filed last month, Elanco said its collar is safe despite reports of more than 86,000 adverse incidents, including 2,340 pet deaths, since it hit the market nine years ago.
Those incidents, Elanco said in its 41-page comment, are probably related to other factors, not the collar. Because the collar is worn for months at a time and always visible on the animal, it’s often cited in any health incident a pet has while wearing it, the Indiana-based company said.
Elanco cited its own extensive studies and investigations into those reports that say the collar is safe. It noted the incident rate has declined as sales increased – from 60 reports per 10,000 collars in 2013 to 17 per 10,000 in 2020.
Elanco’s comment was one of more than 5,400 submitted in response to a petition by the Center for Biological Diversity to ban Seresto. The nonprofit filed the petition in April, weeks after a story by the Midwest Center for Investigative Reporting and Paste BN on the high number of incident reports linked to the collar.
The EPA launched a formal review of the product in response to the petition and opened a 60-day public comment period July 12. A congressional subcommittee asked Elanco to voluntarily withdraw the product. Several class-action lawsuits were filed against the company.
Read the investigation: Popular flea collar linked to almost 1,700 pet deaths. The EPA has issued no warning.
Now that the public comment period has closed, the EPA will review the comments as it decides whether to cancel the collar’s registration. A cancellation would mean the company could no longer use the pesticides in its collars.
The EPA has no official timetable for this process. A review by Investigate Midwest and Paste BN this year found that the agency often takes years to make such decisions.
Elanco, which acquired Seresto in 2020 as part of a $7.6 billion deal with Bayer, said it would not withdraw the collar from the market. Its public comment is its most extensive argument that its product is safe.
The company said in its filing that more than 28 million Seresto collars have been sold in the USA since 2012, and just a fraction of them have been the subject of incident reports. The EPA classified more than 93% of incidents as “minor” or “moderate,” and the pet did not suffer “any significant or permanent harm,” the company said.
Analyses by Elanco and its hired experts found that the pesticidal action of the Seresto collar, which contains the chemicals imidacloprid and flumethrin, did not cause pets to be harmed, according to the company’s comment.
Nathan Donley, a scientist at the Center for Biological Diversity, said he was not surprised by Elanco’s response to the center's petition.
“Of course Elanco’s analysis is going to show there are no problems, they would never conceivably come to any other conclusion. Companies are not capable of regulating themselves or providing any ‘evidence’ that their products are just fine and dandy. Theoretically, that’s why we have regulators. To do independent analyses without any meddling from the companies that want to keep profiting from their products,” Donley said.
Donley said the way Elanco calculated its incident reporting rate is incorrect.
“Basically, since most pets use multiple collars (at least the ones that don’t have an adverse reaction), you have to divide the number of incidents by the number of animals treated, not the number of collars sold,” Donley said.
Elanco spokeswoman Keri McGrath said the company’s methodology “parallels EPA’s own guidance on reporting incidence rates, which ensures accurate and consistent evaluation.”
“Extensive research and nearly 33 million uses of Seresto – in the U.S. alone – have amply demonstrated Seresto’s safety profile,” McGrath said in an email.
In the public comment, Elanco touted the benefits of Seresto, which include controlling parasites that can spread Rocky Mountain spotted fever. The Centers for Disease Control and Prevention encouraged the approval of the collar in 2012 to combat the disease.
The American Veterinary Medical Association filed a comment defending the use of the collar, saying the EPA should consider the benefits of controlling disease-causing pests.
The veterinary association said the EPA, if it deems appropriate, could offer “mitigating label language” to warn about sleeping in a bed with a pet wearing the collar.
Many of the other comments were “sign-ons” to the Center for Biological Diversity’s petition to ban the collar.
The center filed Freedom of Information Act requests that resulted in the release of thousands of internal EPA documents. Many of those documents reveal staff in the agency’s pesticide division raised concerns about the safety of the collar. Among the concerns was that Seresto was No. 1 in pet collar incident reports “by a wide margin” as far back as 2015.
The pesticide division issues approvals of the use of pesticides and monitors complaints.
Beyond its initial review of the product before approving its use in 2012, the EPA said, it has not done a formal analysis of Seresto until now.
Elanco said it has “been working for years with outside experts to continue to analyze and monitor incident reports for Seresto.” That analysis showed that 12 incidents of pet death were either “probably” or “possibly” related to the collar, and those deaths were likely due to the physical nature of a collar, the company said.
“It bears repeating that the incident reports do not establish causation of an incident by a product, but only report a potential incident or health issue,” Elanco said in the comment letter.
In 2020, the company sold more than 7 million Seresto collars, and during a typical year, it said, it would expect 365,000 pets to die for a variety of reasons, including old age or being hit by a car. The company said it received 167 reports of pet deaths.
Elanco pointed out that the EPA has repeatedly approved the two active ingredients in Seresto, imidacloprid and flumethrin based on eight companion animal safety studies and more than 90 toxicity studies in lab animals.
From 2012 to 2020, the EPA received 1,153 reports of human harm, according to Elanco. Forty of those were classified as major, 400 as moderate and 713 as minor. There were no reported human deaths associated with the collar.
Incidents listed by the EPA included:
•A 12-year-old boy who slept in a bed with a dog wearing a collar had seizures and vomited. He had to be hospitalized.
•A 67-year-old woman who slept in a bed with a dog wearing a collar reported having heart arrhythmia and fatigue.
•A 43-year-old man put collars on eight dogs and slept in the same bed as four of them. A week later, he developed ear drainage and nasal and throat irritation and was told by a doctor that he had a hole in his ear drum. He removed the dog collars, and the symptoms went away. He reapplied the collars, and the symptoms returned.
Elanco said the company’s analysis found that 153 of those reports were “probably” associated with the collar, and 239 were “possibly associated,” and 161 incidents were “unclassifiable.”
This story is a collaboration between Paste BN and the Midwest Center for Investigative Reporting. The center is an independent, nonprofit newsroom covering agribusiness, Big Ag and related issues. Paste BN funds a fellowship at the center for expanded coverage of agribusiness and its impact on communities.