The U.S. Environmental Protection Agency is intensifying its evaluation of whether further restrictions on the use of spot-on pesticides for flea and tick control are necessary to better protect pets. The increased scrutiny applies to both over-the-counter and veterinary channel flea and tick products.  An EPA spokesman said the move follows recent increases in reported incidents. More than 44,000 potential incidents associated with registered spot-on products were reported to the agency in 2008.  

Federal law requires EPA registrants to submit reports of possible adverse reactions that may be related to the use of their products whether or not the products were used properly and according to label instructions. A report does not indicate a cause-and-effect relationship between products and symptoms. EPA spokesman Dale Kemery said restrictions under consideration could include additional and more detailed label claims. “I just can’t say at this point,” Kemery said. “That’s what the evaluation will indicate.”  

Though flea and tick product incidents can involve spot-ons, sprays, collars and shampoos, most incidents reported to the EPA are related to EPA-registered spot-on products.  Spot-ons are generally sold in tubes or vials and applied to one or more localized areas on the pet, such as between the shoulders or along the back. The active ingredients in these products are amitraz, cyphenothrin, dinotefuron, etofenprox, fipronil, imidicloprid, metaflumizone, permethrin, pyriproxyfen and S-methoprene.  

Adverse reactions reported in relation to the products range from skin irritation to seizures and in some cases death, according to the EPA.  

The EPA encourages veterinarians to report any incidents through a new reporting page developed by the EPA and the National Pesticide Information Center at  

In the EPA’s Crosshairs
At the time of the April 16 advisory, the EPA expressed concern about products from seven companies in both the veterinary and over-the-counter channels. But, several weeks later, the EPA extended the list to include all EPA-registered spot-on flea and tick products. Click here for the full list of available products. EPA officials said their initial list might have led consumers to believe that only the products previously listed were of concern, when in fact, the agency is evaluating all spot-on products.  

Specifically, the EPA is checking reports of adverse reactions, product market share, clarity of product directions and label warnings, product ingredients and pre-market safety data submitted in support of registration of these products.  

Its assessment could lead to changes in the registration status of certain spot-on products.  Of particular concern is the potential misuse of these products by consumers, according to the manufacturers.  

Vets Play Key Role
Common misuses include pet owners applying a spot-on product dose that is inappropriate for the pet’s size and applying a product designed for a dog on a cat and vice versa, said Hal Little, DVM, director of field veterinary services for Merial Ltd. of Duluth, Ga. That is why following instructions and working with a veterinarian are so important, he added. “The veterinarian is a very important gatekeeper,” Dr. Little said. “Clients should be working with their veterinarian, asking questions, talking about directions and about the products.” Merial maintains that while the EPA noted a “sharp increase” in the number of reported adverse events associated with spot-ons, company records do not indicate such a case for Frontline.  

“The number of adverse events reported per volume of sales has remained consistently low since the introduction of Frontline in 1996,” Little said. “Over 1 billion doses of Frontline have been sold, so there is extensive experience with the product in marketed use.” Merial and other spot-on product manufacturers are working with the EPA. A meeting was to be held in May in conjunction with the Canadian health department, which has identified similar concerns.  

Fort Dodge Animal Health of Overland Park, Kan., is working closely with the EPA to identify and resolve any issues related to ProMeris for dogs, spokes-man Ryan Noonan said.  

“Before ProMeris for dogs was released to the market in 2007, it went through extensive clinical testing,” Noonan said. “Because ProMeris is a new product, there may be more questions related to its use, as compared to other available spot-on products that have been on the market for a number of years.”  

Mark Levin, vice president of technical affairs at Sergeant’s of Omaha, Neb., said he thinks the increased number of reports can be tied to the fact that products traditionally sold through the veterinary channel are being sold over the counter. “The one item we feel we at least need to get on the table … is that when (veterinary products) are sold to a consumer and the consumer has an issue with that product, they take it and the animal back to the vet,” Levin said. “The vets don’t necessarily report those adverse events back to the manufacturer. Whereas for our over-the-counter products, if a consumer has a problem with our product, they call us directly and we respond with those numbers to the EPA.”  

In regard to reports of incidents involving Sergeant’s products, Levin said those numbers are low. “We don’t feel good about even one case, and we constantly look at any opportunity that we can to improve our products across the board,” he said. For example, Levin said the company has found cases in which consumers used the wrong size product or used the product on the wrong species. Levin said the company also found cases in which household pets licked each other shortly after application.  

Melinda Fernyhough, DVM, Ph.D., manager of Scientific Affairs for Hartz of Secaucus, N.J., agrees that reading the label carefully is important. “Hartz wholeheartedly endorses the EPA advisory’s call to action to pet owners regarding the importance of carefully following label directions and making informed decisions when selecting and using spot-on flea and tick pesticides,” Dr. Fernyhough said. “As the EPA states: ‘The pesticide label is your guide to using pesticides safely and effectively.’” Fernyhough said that EPA-reported adverse effects for Hartz UltraGuard products for cats decreased in 2008 from 2007 and those for Hartz UltraGuard for dogs maintained the same low ratio of reported incidents to sales.  

Matter of Perspective
One needs to temper the 44,000 potential incidents with the available units for sale in the field, said Mark Newberg, director of corporate affairs at Central Life Sciences of Schaumburg, Ill. In that context, he said, the number of adverse reactions turns out to be very small. “And of those 44,000, I’m going to guess that the lion’s share are mild or moderate reactions,” he said. Newberg said he believes that many of the reports involve consumers applying the product incorrectly. For example, he said, because of the ailing economy, some consumers buy a product for a larger animal and mete it out over several months instead of buying the proper dose. “It may sound like something that everybody is preaching, but (it comes down to) the label directions,” Newberg said. “Nowhere on the label directions do you see, ‘Split up doses.’ It says very clearly, ‘Do not use these products on cats’ when they are designed for dogs. I don’t know how much clearer you can be.”  

What more can be done?  

“That’s exactly what the EPA meeting is for,” Newberg said. “Once we put the cards on the table, we will have the opportunity to look at the adverse reactions. Maybe there will be a submeeting or subgroup that puts together a task force to look at labeling…They may come back after the meeting and say these instructions are very clear and maybe change the way adverse incidents are reported, so that numbers don’t skew one way or another.” Whatever the result, Newberg said he is anxious to work with the EPA on this issue. TradeWinds, a brand of AgriLabs of St. Joseph, Mo., did not return telephone calls.  

Keeping Watch
With the updated listing, the EPA reiterated that it is not recalling products nor suggesting that these products not be used. “EPA recognizes the importance of the products in effective flea and tick control,” said a statement on the EPA website. “EPA’s objective is simply to advise consumers and pet owners to exercise caution when using the products and to monitor pet behavior following their use.”  

Specifically, the EPA urged pet owners to carefully follow label directions and monitor their pets for adverse reactions, particularly when using a product for the first time. The EPA also recommended that pet owners consult a veterinarian about “the responsible and effective use of flea and tick products.”