The Seresto collar is one of our tools to prevent flea and tick infestation. Most of our clients are using Nexgard, Revolution or Bravecto, but we also recommend the Seresto collar for many patients. It is our most cost-effective flea and tick product and also easy to use as it lasts up to 8 months.
This week, USA Today published an article calling into question the safety of the Seresto collar. I have read the article as well as the response from Elanco, the collar’s manufacturer. The article refers to reports of disease or death in pets that have used the collar, where the owner told the company. The company is required to report adverse events to the EPA, and the EPA compiled a list of these events.
We have not seen any cases in our clinic of anything more serious than skin irritation from the use of the collar. As for the data given in the article, unfortunately it is anecdotal and not very useful for our purpose of deciding on the safety of the device. Here is a list of things that make the raw data not useful:
The product reported might not be Seresto but might be reported as Seresto (a lot of people use Seresto as a generic name like Kleenex).
The product could be counterfeit, as people are unknowingly buying counterfeit collars from online stores. We receive collars directly from the manufacturer, no distributor involved.
The patient could have had the disease before the collar was used.
When the disease is unrelated to the collar, the report looks the same as one that is related.
Reports can be filed even in cases where the person does not have a pet and where the pet never used any collar.
The clinical signs reported may not match the actual signs.
The span of time between illness and death could be very long. There are sometimes reports where a collar was used once at age 3, and then the patient died at age 10, and the person reporting thinks there must be a connection.
In other words, there is no validation of the raw data used in the article. USA Today didn’t do any validation of their own, and only found one case worth publishing on.
The scientific experts that were cited by USA Today were a former employee of the EPA who is unfamiliar with the product and the data, and an activist scientist who made such broad conjectures about medicine, which is not his field, that it really undermined his credibility.
Our experience with the collar is that it has been a very useful and safe device. We have had a few cases of itchy skin and have generally switched products. We have not seen any neurological signs with the product in our years of using it. So we rely on the EPA and the manufacturer to properly validate adverse events and figure out if they are associated with the collar.
There is always the possibility of incompetence or corruption of the companies or agencies responsible for handling adverse event information. If this turns out to be the case, you will know one very angry Veterinarian. But so far I have seen no reason to accuse the EPA, Elanco, or Bayer, the prior owner of Seresto, of such things.
I hope you find this information helpful and I will update it as we learn more.