Caution Urged in Use of Flea, Tick Products for Pets

Environmental Protection Agency Reacts to Reports of Health Problems in Pets

From the WebMD Archives

March 18, 2010 -- In the wake of mounting reports of adverse pet health effects, the Environmental Protection Agency (EPA) has issued new restrictions on spot-on flea and tick products -- and urges extra care in their use.

The products are concentrated pesticides applied from a small tube to the skin beneath the fur on a cat or dog's back. They can keep a treated pet free of fleas and ticks for weeks. Popular brands include Advantage, Bio-Spot, Frontline, Hartz, and Zodiac.

The EPA, which is responsible for pesticide safety, noted an increase in the number of safety reports on these products. In 2009, the agency asked eight manufacturers for detailed information from adverse-event reports on their products.

Those details linked the products to health issues ranging from mild skin irritation to seizures and, in rare cases, to the death of the pet. Because the reports did not account for product popularity -- and because the reports were not verified -- the EPA was not able to identify if any specific products were particularly dangerous.

EPA Actions

Nevertheless, the EPA has announced it is taking several actions:

  • Product misuse, such as using doses intended for large dogs on small dogs, led to many of the negative health incidents. New product labels must carry clearer, more precise instructions.
  • A number of incidents were caused by consumers using dog products on cats. New product labeling requirements will prevent the use of similar names for cat and dog products and require a clear indication of which products are formulated for dogs or cats.
  • New products will receive only conditional approval to allow for post-marketing surveillance.
  • Some of the products' safety issues may be related to inert ingredients. The EPA will investigate these ingredients and restrict their use if necessary.
  • Pre- and post-marketing tests will be required to bring these products into line with regulations required by the FDA for similar products.
  • The EPA is launching a consumer information campaign to educate pet owners about the appropriate use of these products.

The EPA lists eight firms making the products:

  • Bayer (Advantage brands)
  • Fort Dodge (owned by Pfizer, brands include ProMeris for Cats)
  • Hartz Mountain (brands include Control One-Spot)
  • Merial (Frontline brands)
  • Pet Logic
  • Sergeants (brands include Sergeant's and Sentry)
  • Summit Vetpharm (Vectra brands)
  • Wellmark/Farnam (now Central Life Sciences, brands include Bio-Spot and Zodiac)


All of the products were linked to some reports of deaths and other serious events, but the most of the incidents were not serious.

In dogs, the EPA found that:

  • Most of the adverse events involved the dog's skin, gastrointestinal system, or nervous system.
  • Symptoms included vomiting, diarrhea, salivating, itching, hair loss, skin ulcers, lethargy, nervousness, loss of muscle coordination, tremors, and seizure.
  • Small-breed dogs were more likely to be affected. Most incidents were in dogs weighing 10 to 20 pounds.
  • Most incidents were in dogs less than 3 years old.

In cats, the EPA found that:

  • Most of the adverse events involved the cat's skin, gastrointestinal system, or nervous system.
  • Clinical symptoms were similar to those seen in dogs.
  • Many incidents arose from the treatment of cats with products intended for dogs.

Manufacturers' Reaction

WebMD asked each manufacturer to comment on the EPA action. All of those who responded expressed a willingness to work with the EPA to continue to make these products safer.

Mark Newberg, director of corporate affairs for Central Life Sciences, noted that the vast majority of people who use his firm's and other firms' products have no problem at all.

"If you look at the fact that 270 million doses of product [from all companies] were sold, and a rate of 16 incidents per 10,000, it means you have millions of dogs and cats protected from flea allergy dermatitis, tapeworm, and other diseases," Newberg tells WebMD. "These are satisfied customers. But on occasion there are adverse incidents we can't predict."

Bob Walker, director of communications and public policy for Bayer Animal Health, noted that of the 16 incidents per 10,000 doses, few were serious.

"We have done a thorough analysis of our own incident reporting, and Bayer did not see an increase for Advantage over the period cited by the EPA," Walker tells WebMD. "And our rate of adverse incidents is lower than the aggregate rate reported by the EPA."

In a statement provided to WebMD, Hartz Mountain expressed a willingness to work with the EPA on making labeling clearer.


"While Hartz is the leader in flea and tick retail sales, Hartz flea and tick drops account for less than five percent of all adverse effects reported to the EPA in 2008 for topical dog and cat flea and tick treatment," the statement says.

Merial also provided a statement to WebMD.

"Although EPA has said that its initiative was prompted by a 'sharp increase' it had noted in 2007-2008 in the number of reported adverse events related to the use of spot-on flea and tick control products in general, Merial's data does not indicate that this is the case for Frontline. The number of adverse events reported for Frontline has remained consistently low since the product's introduction in 1996," the statement says.

WebMD Pet Health News Reviewed by Audrey Cook, BVM&S on March 18, 2010



Environmental Protection Agency: "Review of 2008 Incident Reports for Pet Spot-on Pesticides."

News release, Environmental Protection Agency.

Environmental Protection Agency web site.

Hartz Mountain, email communication.

Mark Newberg, director of corporate affairs, Central Life Sciences.

Bob Walker, director of communications and public policy, Bayer Animal Health.

Steve Dickinson, head of global corporate communications, Merial, email communication.

© 2010 WebMD, LLC. All rights reserved.


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