In our on-going war against parasites, “spot-on” medications have vanquished billions of blood thirsty fleas.  But, along the way thousands of pets have suffered significant, even deadly, adverse reactions.  Is this an acceptable trade-off and risk?  Should we take these kinds of chances with our pets’ health?

For more than a decade, pet owners have relied on flea and tick products that claim safe and effective solutions to a persistent problem.  Historically, pesticides to control fleas and ticks were harsh and seemingly caused as many problems to the pets as they did to the parasites.  With the advent of new topical or “spot-on” products, pet owners breathed a sigh of relief.

But now the EPA has raised a red flag and is warning pet owners about serious adverse effects seen with the use of these products.  Citing a “sharp spike” in reported incidents, the EPA has increased scrutiny and may consider restricting their use.

Many different spot-on products are available to pet owners, both through their veterinarians and over-the-counter (OTC) outlets like grocery stores.  Since these “medications” are regulated by the EPA and not the FDA, there is no need for a prescription, allowing anyone from the local pet store to individuals on Ebay to sell the products.

Veterinarians have long thought that significant severe reactions were the hallmark of OTC merchandise.  After all, some OTC flea and tick shampoos, powders and even spot-on products rely on older, potentially dangerous ingredients.  But, even newer medications aren’t immune to problems.  Hartz® was forced to change labeling instructions after several highly reported adverse events with their cat product and eventually pulled it from the market.

Along with Hartz, Farnam and Sergeants also make popular OTC flea preventives and they have all seen their share of reactions along with negative publicity.   In a Center for Public Integrity (www.publicintegrity.org) investigation, all three were singled out for using “pyrethroid type” ingredients. View the original EPA incident report summary

Pyrethroids are the man-made cousins of pyrethrins, a naturally occurring insecticide produced by the chrysanthemum plant.  Unfortunately, pyrethrins breakdown in sunlight and don’t have any sort of residual effect, making constant reapplication necessary.  The improved pyrethroids offered longer lasting protection, but some fear it comes with significant costs.

The recent EPA announcement not only included several OTC flea products, but also two preventives sold primarily through veterinarians.  Generally considered safer than their OTC counterparts, seeing Frontline® and ProMeris® on the EPA’s list was a shock to many veterinarians.

So, does this news mean that we are flirting with danger whenever we use any flea product?

The EPA has not released any particular details of the 44,000 adverse events reported in 2008.  At this time, it is unknown whether more serious reactions are associated with a smaller group of products or if the larger market share of a product places it on the EPA’s watch list.

Even more concerning is that there is no firm proof that any of these products can be linked with the adverse events reported.  Manufacturers are required by law to report any reaction to the EPA, but most of these events come directly from consumers.  The EPA admits that they do not confirm the authenticity of these reports and it is a rare pet owner who is also trained in toxicology.  Many pets also receive booster vaccinations, heartworm preventive and other medications at the same time as their flea control.

Dr. Hal Little, Director of Field Veterinary Services for Merial, maker of Frontline®, says their internal records do not indicate any increase in adverse events associated with that product.  “In fact,” he continues, “the number of reported adverse events has remained consistently low since Frontline’s® introduction in 1996.”

Furthermore, Hartz has stated to veterinarians that their products are often unfairly blamed for these reactions because consumers mistakenly refer to Hartz even though they purchased a competitive flea medication.

What can you do to help keep your pet flea free and safe?  First, read and understand all label instructions for any flea product you might give to your pet.   Veterinarians across the country are reporting many misapplications of the flea medications by owners anxious to stretch their pet health care dollar.  Cats are especially vulnerable to misuse of these products, especially permethrins,  but dogs can suffer as well.

Next, never discard the box of flea medication until you are sure your pet has shown no signs of a reaction.  The box contains ingredient information and EPA registration numbers that are useful if any adverse event occurs. Follow the label directions, do not give  topical (on the skin) medications orally (by mouth) and vice-a-versa, and do not use products labeled for dogs on cats.

Finally, follow the guidance and recommendations of your veterinarian.  They completely understand how flea products work and how to handle any potential problems.  Your veterinarian will also be up to date on the most accurate scientific data showing which products provide the best protection and won’t harm your pet.  In my practice, we are using the flea and heartworm combination products because of the high incidence of heartworms and other parasites. For effective control, we recommend applying these products once a month all year round. As Dr. Little remarked, “this information is important to the health and well being of your pets”.

To learn more about fleas and ticks, be sure to visit www.MyVNN.com to see videos or visit www.PetDocsOnCall.com to ask questions of veterinary experts.

Debra Garrison, DVM