On March 3, 2021, USA Today published an article with this alarming headline:
‘Popular flea collar linked to almost 1,700 pet deaths. The EPA has issued no warning.’
The collar in question is Bayer brand’s Seresto flea and tick collar for dogs and cats, now sold by Elanco, which acquired Bayer Animal Health in August 2020. Since Bayer introduced the collars in 2012, more than 25 million have been sold in the U.S. The collars are effective at controlling fleas and ticks for eight months.
We understand how clients reading the USA Today article would be deeply concerned—especially if their pets wear Seresto collars!
On our first read-through, we found the article concerning ourselves!
After all, we’ve been recommending these collars for years as a convenient, effective alternative to monthly oral and topical preventives. We sell them in our online store.
However, in all our years of recommending Seresto collars for our patients, we’ve witnessed no such severe side-effects as described in the USA Today article. We’ve heard no such stories from other veterinarians, nor have we read about them in veterinary medical publications. The clients who use Seresto collars for their pets seem to love them.
So are Seresto flea and tick collars safe?
Rather than look to the popular press for definitive veterinary medical information, we decided to find out what veterinary toxicologists—none of whom were interviewed for the USA Today article—have to say in response to the article.
Here’s what we found:
While the article alluded to numerous consumer reports to the Environmental Protection Agency (EPA) implicating the collars in the deaths of nearly 1,700 pets, injuries to tens of thousands of pets and health problems for hundreds of pet owners, there is no way to know for sure, based solely on raw, unverified anecdotal evidence, that the collars actually caused such a myriad of problems.
’The signs are very random.’
Quoted in an article published by the Veterinary Information Network (VIN) on March 5, 2021, Dr. Tina Wismer, medical director at the ASPCA Animal Poison Control Center and a toxicology consultant for VIN, said, “Looking at these reports, these are very random things, ranging from ruptured eardrums — which I can’t make fit really at all — to liver failure, to heart problems, to kidney failure. The fact that the signs are very random makes me think that probably [the collar] is not involved.”
‘You cannot make a cause-effect connection.’
A second VIN toxicology consultant, Dr. Sharon Gwaltney-Brant, pointed out that consumer reports to the EPA are often anecdotal and unverified. “Anyone can report anything to regulatory agencies,” she said. “That doesn’t mean it’s true or accurate. This is why looking at the raw data from these agencies is so dangerous — they reflect only the reports, not any ancillary information required to determine if there’s actually any merit to the report.” She added without a veterinary examination or necropsy (an animal autopsy) to rule out other potential causes of illness or death, “you cannot make a cause-effect connection.”
‘The toxicity of these collars is extremely low.’
On a listserv for veterinary toxicologists, Gwaltney-Brant said her colleagues expressed surprise at the concerns about Seresto collars. Even when pets ingest the collars—which happens fairly often with dogs—she said, “the toxicity of these collars is extremely low, and they have no ‘red flags’ on this particular product.”
‘You don’t necessarily know where these collars are coming from.’
Both toxicologists agreed the prevalence of counterfeit products could make it difficult to interpret the incident reports. Fake collars, packaged to look like the real thing and usually priced somewhat lower than the genuine product, may not only fail to protect pets from fleas and ticks but contain ingredients that do harm pets.
“You don’t necessarily know where these collars are coming from and what actually is in them,” Wismer said. “And that could explain a lot of the different kinds of clinical signs we are seeing.”
‘We feel very comfortable with the safety profile of these collars.’
An article titled “Collar-Gate,” published on March 5, 2021, in The Canine Review called the USA Today report “flawed, incomplete, and misleading.”
The article quoted American Board of Veterinary Toxicology President-Elect Dr. Ahna Brutlag as saying, “We feel very comfortable with the safety profile of these collars.”
Dr. Brutlag is the Director of Veterinary Services at the Pet Poison Helpline and has worked with the Helpline since 2004. During that time she said she has not seen any examples of serious adverse events connected with Seresto collars. “Our data has really shown that the collars are not associated with severe adverse events.”
Dr. Brutlag noted that the active ingredients in Seresto collars—imidacloprid and flumethrin—are widely used and based on experience, have “a pretty wide and favorable safety profile for the collars.”
Until we see solid scientific proof, and until our own profession issues warnings, we intend to keep recommending Seresto collars.
Veterinarians weighing in on a VIN message board about the matter have been contacted by concerned clients—as we have. Like us, after years of recommending the collars, they have had very few if any serious adverse reactions to the collars reported.
And until we see solid scientific proof of a direct, causal connection to serious adverse reactions, we intend to keep recommending Seresto collars.
Rest assured, if any solid medical evidence of harmful effects of Seresto collars does emerge in the aftermath of the USA Today article, we veterinarians will be among the very first to know and to respond immediately and appropriately to keep our patients safe. The safety and wellbeing of your pets always has been and always will be our first priority!
Meanwhile, here are a few more points to keep in mind:
In our part of Indiana, we strongly recommend some form of flea and tick control year-round.
All flea and tick preventives come with some degree of risk of adverse reactions, but the risks of discomfort and diseases spread by fleas and ticks to animals and humans far outweigh those risks.
If you are currently using Seresto collars and the concerns about them have you feeling uneasy, we encourage you to click through and read the articles linked to on this post. Then talk to any of our veterinarians about oral and topical alternatives to protect your pet and your family from flea- and tick-borne diseases.
Before using Seresto collars—or any other pet product or medication, for that matter—discuss the risks to your particular pet with your veterinarian, read the entire label and follow instructions to the letter.
Counterfeit pet care products are widely offered by independent sellers through Amazon, Ebay and other online sources, usually at a lower price than the genuine product. Make sure you buy genuine Seresto collars and other pet supplies only from reputable sources. We guarantee any products you buy in our office and through our VetSource online store are the real thing.
With any flea and tick preventive in any form, watch your pet closely after administering it—especially for the first time—and call us immediately if you see any signs of discomfort or distress.