CHICAGO (NewsNation Now) — An investigation found that more than 75,000 complaints about the Seresto brand of flea and tick collars have been sent to the Environmental Protection Agency. Investigators have linked the deaths of nearly 1,700 dogs and cats, according to a report co-published by Midwest Center for Investigative Reporting and USA TODAY.

The collars use two types of pesticides to kill fleas and ticks. The EPA said the collars are safe but that some pets may be sensitive to the pesticide combination.

“I know one of the biggest concerns that people have: ‘We hate ticks. We hate fleas.’ And so do I, but when I go out in the woods, I don’t put a pesticide collar around my neck so that I don’t get fleas and ticks, because I know it’s probably a bad idea to have a pesticide on me,” said Dr. Barbara Royal.

The Chicago-based veterinarian joined NewsNation Prime on Saturday to discuss the reporting.

“It’s disturbing because I know people are always trying to find something a little bit less toxic and effective at the same time, and it can be very difficult for them to find a product that’s going to work,” she said.

The popular collars, sold at Amazon,, big-box pet stores and often in veterinary offices, release a small amount of the pesticides over eight months.

The EPA regulates pesticides. NewsNation reached out to the agency about the reporting but has yet to receive a response.

“No pesticide is completely without harm, but EPA ensures that there are measures on the product label that reduce risk,” an EPA spokesperson told USA TODAY and the Midwest Center for Investigative Reporting. “The product label is the law, and applicators must follow label directions. Some pets, however, like some humans, are more sensitive than others and may experience adverse symptoms after treatment.”

Dr. Royal, the founder and owner of the Royal Treatment Veterinary Center in Chicago, said these collars are a bad solution to a difficult problem.

“These flea collars, they seem like they might be less toxic, but people leave them on sometimes too long, or they’re leaving them on all the time, which may be too much. The extended-release type flea collars, those actually increase the risk of having a toxic event because they’re putting out something that’s going to and last longer and maybe be a little bit more variable in how much pesticide is put onto your dog,” she said.

So, what should pet parents do if they are hesitant about using flea and tick collars? Dr. Royal said one option is essential oils because ticks don’t link some of the scents, but she said you have to be extra careful with cats.

“Being open to different types of things that are out there is not a bad idea, and then also watching your pet and being careful. So, it may be a little more labor-intensive, but it’s sort of fun to spend after a good walk in the woods, spend some time looking through your pet, making sure your checking for the ticks.”

NewsNation also reached out to Elanco, the pharmaceutical company which owns Seresto, but has yet to hear back.

The company did post a statement on their website following the report, saying “there is no established link between death and exposure to the active ingredients contained in Seresto.”

Elanco takes the safety of our products very seriously, and thoroughly investigates potential concerns related to their use. It is critically important to understand that a report is not an indication of cause. Since its initial approval in 2012, more than 25 million Seresto collars have protected dogs and cats in the U.S. from fleas, ticks and the resulting tick-borne illnesses that can impact their quality of life.

– There is no established link between death and exposure to the active ingredients contained in Seresto.
– The reporting rate for all adverse events related to Seresto is less than 0.3% of all collars sold since 2012 – defined by the WHO (World Health Organization) as “uncommon”.
– The significant majority of these incidents relate to non-serious effects such as application site disorders – reddening of the skin or hair loss below the collar.
– As a globally marketed product, more than 80 regulatory authorities around the world, including the US EPA, rigorously reviewed the safety data collected over the course of Seresto’s development prior to registration and/or approval, as appropriate.
– Further, the safety and efficacy of Seresto are continuously monitored and scrutinized by global regulatory bodies as well as via internal processes.

Elanco statement