Label changes are under way for spot-on flea and tick preventatives, and while modifications are still in the works, one warning is likely to be stressed: Topical pet parasiticides intended for dogs can be fatal if used on cats.
That change and others like it are coming via pressure from the U.S. Environmental Protection Agency (EPA), which has been investigating a surge in adverse events reportedly tied to spot-on parasite-control treatments, with reactions ranging from minor skin irritations to seizures and deaths.
The EPA began looking at the issue three years ago
, when the number of reported adverse events in pets exposed to topical flea and tick products reached 44,000 in 2008, up 53-percent compared with the previous year.
In response to the 2008 increase, the EPA analyzed 21 different products registered by Bayer, Fort Dodge Animal Health (now Pfizer), Hartz Mountain Corp., Merial, Pet Logic, Sergeant’s Pet Care Products, Inc., Summit VetPharm and Wellmark. The topical parasiticides produced by these companies are considered “spot-on” because they come as liquids contained in small, plastic vials that are squeezed onto the skin of a pet’s back, usually between the shoulder blades. Spot-on treatments typically are applied every few weeks during flea and tick season to prevent and manage infestations.
The EPA regulates these products because they're categorized as
pesticides rather than drugs, which are controlled by the U.S. Food and
Drug Administration. Any formula to treat fleas and ticks that does not cross the skin barrier must be EPA-registered. The topical products in question include active ingredients in all pesticide classes: cyphenothrin, phenothrin, permethrin, imidacloprid, dinotefuran,
fipronil, amitraz, etofenprox, S-methoprene, pyriproxyfen and
Some, including veterinarians, pet owners and manufacturers, blame product misuse for the rise in adverse events associated with spot-on flea and tick treatments. In March 2010, the EPA concluded that spot-on labels needed to better warn against using treatments meant for dogs on cats. The agency also wanted manufacturers to lower recommended dosages for some pets in hopes that fewer animals would become over-medicated.
The EPA continues to back this stance despite the fact that adverse reactions to spot-on flea and tick treatments more recently have declined in numbers. In 2009 and 2010, adverse events reported to the EPA totaled 38,062 and 27,532, respectively. Aggregate
numbers for 2011 have not been calculated.
The EPA attributes the decrease to
a variety factors, including increased public awareness that flea and
tick treatments can induce negative and sometimes life-threatening side
effects in pets, especially if used incorrectly.
To mitigate future incidents, the agency continues to pursue label modifications. In a seven-page letter
to spot-on registrants dated Sept. 30, 2011, the EPA asked companies selling spot-on treatments to submit within six months a draft of label and packaging changes that include, in part:
• Enlarged label font sizes and animal images that allow users can quickly distinguish the species for which the product is intended;
• Specific language on labels of products intended for dogs that warns against their use on cats; repeating the words "dog" and "cat" throughout product instructions; and adding a “cat prohibition icon” to the lower right corner of packaging for canine flea and tick treatments;
• More information about possible adverse events and instructions for pet owners to contact the product manufacturer and a veterinarian if a suspected reaction occurs;
• Narrowed product weight ranges and appropriate pictures of the weight ranges;
• More clearly defined species, age and weight ranges.
It's unclear whether manufacturers ultimately will make all of the EPA's suggested label changes; the six-month window for submitting draft language to the EPA ended in April. While the EPA indicates that it's going back and forth with companies to approve new labels and packaging, regulators would not identify whether any changed labels currently are in the marketplace.
"The agency is beginning to see applications for amendments to product labels in response to the EPA letter," spokesman Dale Kemery said in response to a query from the VIN News Service. "Over the next few months, EPA will be reviewing these amendments … to ensure that the necessary changes are adequately addressed.”
Kemery continued: “Some registrants are proposing alternate language or an alternate approach to address the mitigation changes requested” in the EPA’s letter. “EPA has considered those approaches and responded to those registrants' requests individually."
FidoPharm, maker of the generic fipronil-based flea and tick killer PetArmor, already has altered packaging on the store shelves. In a news release
issued Feb. 28, the company stated that the packaging enhancements included enlarged images of dogs and cats as well as reminders that the product should only be used on the type of pet indicated.
"PetArmor's new packaging proactively addresses many of these requirements ahead of EPA's proposed implementation timeline," the FidoPharm news release stated.
When asked about the status of the EPA-requested label changes, Hartz Mountain Corp. reported that revised labels for its pet parastiticides have been submitted to the EPA for review. The company went more in-depth on its website
to summarize how the EPA's evaluation has impacted Hartz labels that include the spot-on Hartz UltraGuard. In short, Hartz said that it's already in compliance with many EPA-suggested label modifications and is being singled out by regulators as an example of how to present label information that consumers can easily comprehend.
"Hartz made recommendations to EPA about THEIR required language and how
to make it easy to understand. EPA has since issued our suggested
language across topicals for all manufacturers," a company news release stated.
A representative for Merial, the maker Frontline, stated that the company is "still in discussions with EPA about labeling and no decisions have been made yet.” Bayer, which produces Advantage, said it “is working closely with the EPA on this topic.”
Meanwhile, drug makers face several class-action lawsuits
by pet owners who question the safety of chemical- and pesticide-based spot-on treatments with allegations that their use on animals caused skin irritations, paralysis, seizures, death and other adverse incidents.
Drug companies named as defendants are moving to have the cases dismissed, but Michael Green, a New Jersey-based lawyer who helped file several of the class-action lawsuits, said in an interview with the VIN News Service that he expects these attempts to be rejected by midyear. The next step in legal proceedings, he said, will be the discovery phase, during which company executives could be deposed to help prepare for possible jury trials.
Green said he has five lawsuits pending, the most recent filed in December against FidoPharm, maker of PetArmor. Another case
, filed May 2010 in U.S. District Court in New Jersey on behalf of 30 pet owners, seeks injunctive relief in the form of a recall, product refunds and compensatory damages expected to total more than $5 million from Summit VetPharm, maker of Vectra 3D, and Hartz Mountain Corp. The products in question from these companies are spot-on flea and tick treatments.
The lawsuit also names Sergeant's Pet Care Products, alleging that adverse reactions occurred in pets treated with the company's flea and tick powder as well as a shampoo containing the synthetic insecticide permethrin.
The case, which lists Green and attorneys from nine other law firms as plaintiff representatives, recently was consolidated with other class actions like it.
Bayer, Farnam, Merial and Wellmark are named as class action defendants in other cases. None of the companies identified would comment about ongoing litigation.
VIN News Service commentaries are opinion pieces presenting insights, personal experiences and/or perspectives on topical issues by members of the veterinary community. To submit a commentary for consideration, email email@example.com.