EPA Investigating Pet Incidents Involving Seresto Collars

The collars were named in more than 75,000 incidents where pets were harmed, federal records show. The company that makes them rejected a request for a temporary recall, saying its data 'supports the product’s safety profile and efficacy.'

NBCUniversal Media, LLC

There are new safety questions about one of the leading flea and tick collars on the market.

Some members of Congress want the maker of Seresto products to temporarily remove them from store shelves. That request came after new federal records showed Seresto collars were named in thousands of incidents where pets were harmed.



Watch NBC10 Boston news for free, 24/7, wherever you are.


Get Boston local news, weather forecasts, lifestyle and entertainment stories to your inbox. Sign up for NBC Boston’s newsletters.

The Environmental Protection Agency is also investigating the circumstances after a report published last month by USA Today highlighted the number of events the agency has documented involving Seresto collars.

The collars contain a pair of pesticides approved for use by the government.

Under federal law, manufacturers of pesticide products are required to report any adverse events involving those goods.

A summary of those incident reports shows Seresto collars were named in more than 75,000 incidents, including 1,698 reported pet deaths. The reports were filed between 2012 and June 2020.

“When you're seeing numbers this high, that's not an anecdote. That’s not a weird coincidence,” said Nathan Donley, senior scientist at the Center for Biological Diversity, an activist environmental group that obtained the data through a federal records request.

Reports of harm associated with the collars range from relatively minor effects, such as animals suffering itchiness and skin irritation, to seizures, convulsions and pet deaths, Donley said.

“EPA needs to look into this quickly and come up with some answers very quickly,” he said, “and at the same time, be very transparent with the public of what they're doing and what they're thinking.”

Seresto Collars were first introduced by German pharmaceutical giant Bayer, which completed the sale of its animal health division to Elanco in August 2020. Bayer didn’t directly address questions NBC10 sent this month, simply saying they no longer make or sell the product.

A spokesperson for Elanco said drawing a causal link between Seresto collars and harm described in individual incident reports is misleading.

More than 25 million Seresto collars have been sold since 2012, and the rate of adverse incidents involving Seresto products last year was only a fraction of 1%, according to the company.

The significant majority of those events were “non-serious effects,” like hair loss below the collar, according to a company spokesperson.

She added that there is no established link between exposure to the active ingredients in Seresto and pet death.

“We take the safety of our products very seriously and thoroughly investigate potential concerns related to their use,” the spokesperson wrote. “All data and scientific evaluation used during the product registration process and through Elanco’s robust pharmacovigilance review supports the product’s safety profile and efficacy.”

At the Scituate Animal Shelter, Dr. Martha Smith-Blackmore says she continues to recommend Seresto because she believes it’s safe and effective.

“You can put it on your dog at the beginning of the season, and it lasts for eight months, so it's basically a set-it-and-forget-it solution,” she said.

The EPA told us it hasn’t identified any “unreasonable adverse effects” to people or the environment from the two pesticides used in Seresto, imidacloprid and flumethrin.

The agency is in the early stages of reviewing pet incidents, and can’t yet conclude whether Seresto has a higher rate of harmful events than similar products, it said.

A spokesperson said the EPA is currently requesting detailed information about pet incidents involving Seresto, and about the registered pesticides it uses.

“EPA understands this is a critical issue,” the spokesperson said. “The agency’s immediate advice to pet owners is to talk with their veterinarian before using any pet insecticide to find out what the vet recommends, read the label, and follow instructions on safe use of the product, be alert for any unexpected reaction, and report adverse reactions with as much detail as possible.”

Members of the congressional House Subcommittee on Economic and Consumer Policy are also investigating the issue.

They called on Elanco last month to immediately institute a temporary recall of all Seresto flea and tick collars, and requested a range of company records, including internal documents relating to toxicity or risks of death and injury to pets or humans.

The company has rejected the recall request, saying there is no medical or scientific basis for one.

“Elanco is cooperating with the Subcommittee’s request for information and looks forward to explaining how the initial media reports on this topic have been widely refuted by toxicologists and veterinarians,” a spokesperson wrote.

For pet owners weighing the news, Smith-Blackmore says the best move is to consult a veterinarian about what’s safe for your dog or cat.

“In New England, you have to be doing something for fleas and ticks, and in particular for any animal that goes outdoors,” she said. “Because Lyme disease is rampant in our area and it can be fatal.”

Contact Us