Investigating allegations that flea and tick collars may cause harm to pets.  According to a recent report it is alleged "Seresto, one of the most popular flea and tick collars in the country, has been linked to hundreds of pet deaths, tens of thousands of injured animals and hundreds of harmed humans, U.S. Environmental Protection Agency documents show."​

A spokesperson for Elanco, a pharmaceutical company that sells pet collars for Bayer, reportedly stated in part that "There is no established link between death and exposure to the active ingredients contained in Seresto."