Seresto Flea Collars Tied to Over 1,600 Pet Deaths in U.S. Since 2012

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Seresto pet collars are offered for sale at a retail store on March 03, 2021 in Chicago, Illinois.
Seresto pet collars are offered for sale at a retail store on March 03, 2021 in Chicago, Illinois.
Photo: Scott Olson (Getty Images)

Seresto, a popular flea collar produced by the company Elanco Animal Health, has been tied to over 1,600 pet deaths in the U.S. alone since 2012, according to a new investigation by USA Today. But the U.S. Environmental Protection Agency, which regulates flea collars and any other pet treatment containing pesticides, still refuses to act.

USA Today has uploaded the documents it gained access to through a Freedom of Information Act (FOIA) request, including the aggregate incident summaries about Seresto, which show over 75,000 incidents reported and 1,698 pet deaths linked to the flea collars between 2012 and June 2020. The pet collars were first introduced to consumers in 2012.

USA Today even spoke with a former EPA employee, Karen McCormack, who claims the agency has known about the dangers of the Seresto collars for years but have been, “turning a blind eye to this problem.”


It’s unclear why the EPA would refuse to issue some kind of warning about Elanco’s Seresto flea collar, but the actual number of illnesses and deaths are likely much higher that the official reports. Making a report to the EPA about a dangerous collar requires a pet owner to first make a mental connection that the collar was the cause of the illness. After that, making a report to the EPA requires a good deal of time and effort, but we know that at least 1,698 people have done just that about their dead pets since 2012.

A spokesperson for Elanco told USA Today that the Seresto collar has been approved for use in 80 countries, but that doesn’t actually prove much when you look at product reviews around the world. As one example, the Seresto flea collar has a rating of just 1.7 out of 5 stars on an Australian review website, with 26 ratings. The reviews are filled with warnings about pets having severe reactions and paralysis.


“My Labrador is at the vets now fighting for life, we have been buying these in good faith believing them to be trustworthy.... never again. I just hope that we have got to him early enough,” one Australian review from June 2020 reads.

Amazon reviews for the collars around the world have much higher ratings, but some of the reviews still show similar concerns and include dire warnings from pet owners who didn’t know any better.


Elanco was a subsidiary of the pharmaceutical company Eli Lilly until it was spun off in 2019. Elanco Animal Health spent roughly $785,000 in lobbying U.S. politicians in 2020 and $860,000 in 2019, according to the transparency organization Open Secrets.

You can read USA Today’s full investigation at its website.