In the latest information about Seresto flea and tick collars for dogs and cats, reports include at least 2,698 pet deaths and nearly 900 human incidents.

More

UPDATE: This story was updated at noon Nov. 7, 2022, with a response from Elanco.

The Seresto flea and tick collar now has been the subject of more than 100,000 incident reports, according to new EPA documents.

The popular parasite treatment for dogs and cats has come under criticism in recent years, after Investigate Midwest and USA Today reporting showed that Seresto is the most complained about product in U.S. Environmental Protection Agency history.

The collar has now been the subject of 101,486 incident reports, including at least 2,698 pet deaths and 894 incidents involving humans, according to an incident report obtained by the nonprofit Center for Biological Diversity and shared with Investigate Midwest. That data is through Oct. 5.

This is 3,000 more incidents than were reported in June, when a Congressional subcommittee released a report recommending that the product be removed from the market by the EPA and asked Elanco, the maker of Seresto, to voluntarily recall the product. Rep. Raja Krishnamoorthi, D-Ill., the chairman of the subcommittee, sent another letter in July asking EPA administrator Michael Regan to remove the product.

"These numbers are just crazy. This is 25 people calling in every day for the past 10 years," said Nathan Donley, environmental health science director at the Center for Biological Diversity. "The sheer volume of incidents that people have actually taken time to tell Elanco and the EPA kind of blows your mind. It was incredibly surprising to us."

The EPA has announced it is formally reviewing Seresto, after the Center for Biological Diversity submitted a petition asking for the product to be removed. New documents obtained by the center show that, in June, the EPA thought that a scientific review of Seresto would be finished by September, but that the agency in July estimated the review would be finished in the "fall."

"We do not have a solid time frame for any regulatory decision that may come out of the review of the science assessment," wrote an EPA scientist in July.

The EPA did not respond to a request for comment about where that review stands.

Donley said he believes the number is an underestimate — a concern shared by EPA scientists.

"I can't think of how many more people never thought to call anyone or never made the connection," he said.

The EPA's Office of Pesticide Programs is in charge of regulating pesticides, including pet products. EPA scientists, including a veterinarian, have cast doubts on the agency's ability to properly regulate pet products, according to documents previously obtained by USA Today and Investigate Midwest. EPA management has considered transferring responsibility of pet products to the Food and Drug Administration, which regulates pet medicine, documents have shown.

The EPA’s Inspector General also has launched a review into the agency’s handling of the complaints associated with the product.

Elanco spokeswoman Colleen Dekker reiterated in an emailed statement, sent after publication of this story, that the company believes Seresto is safe based on its own internal studies, and an incident report does not mean that Seresto is responsible. Dekker also noted Seresto has significant benefits.

"It provides eight months of continuous, affordable coverage against fleas and ticks, which can carry serious and potentially fatal diseases, like Lyme disease and Rocky Mountain Spotted Fever. These diseases can potentially infect both pets and humans and their incidence is on the rise — CDC estimates approximately 500,000 human cases annually. Seresto offers a much-needed, cost-effective option for protection," Dekker said.

An Investigate Midwest review of the EPA database of pesticide products shows that while Seresto is the most complained about product in EPA history, many other pet products also have high incident reports. The database is up-to-date through March 22, 2022.

Triforce Canine Squeeze-On, which was discontinued in February 2013 at the manufacturers’ request, led to 62,294 complaints in just six years on the market.

Frontline Plus, a top spot-on competitor containing the pesticide fipronil, has led to 61,949 complaints, including 858 deaths of dogs and 733 deaths of cats.

K9 Advantix and Advantage, imidacloprid-based products sold by Bayer, have led to at least 59,568 complaints, including at least 1,178 deaths.