Pesticides and You

Divergent philosophies about poisons and flea control divide our readers.


Never, in the five-year history of WDJ, have we published an article that got our readers’ attention – and divided them into two disparate camps – as Kathleen Dudley’s examination of spot-on pesticides (“Are Spot-On Flea Killers Safe?” February 2002). And that’s interesting, because we’ve always discouraged our readers from using pesticides on and around their dogs, as part of the effort to reduce the toxic burden that most dogs labor under in their short lives.

Fortunately (for us!), about 90 percent of the calls, letters, and e-mail messages we received were appreciative of the article and its follow-up piece, “Eliminate Fleas Without Poisons,” published in the March issue. Some readers wrote to express how pleased they were to see an article that was critical of these products in print:


“Thanks for such an educational, honest article. The main reason I subscribe to WDJ is that it is difficult to get honest, unbiased reporting in other publications. I look to you to continue to report honestly on all sides of current canine health issues – how else are we going to learn about them?”

“I want to thank you for your informative article on flea treatments. The article was clear, concise, and gave me information I can’t seem to get from my veterinarian.”


Others wrote in to confirm that they have found non-toxic flea control methods to be effective and worthwhile:


“Our two-dog, three-cat household has been flea-free for nearly 10 years without pesticides. I’m convinced that the best defense against fleas is to have the healthiest animals possible.”


By far the most rewarding letters for me to read were the letters from dog guardians who corroborated Dudley’s assertions – including people who have witnessed the acute or chronic effects of these pesticides on their own dogs:


“What an eye-opening article! I almost jumped off the couch when I read the segment where the San Diego veterinarian’s clients stated they put Advantage on the backs of their dogs and could smell it on the dogs’ breath in a matter of minutes following the application! That is exactly what I told my vet, who told me that it wasn’t possible! I will no longer use these products.”

“I just received some information on Bayer’s product, Advantage, also obtained through the Freedom of Information Act. Within one year of its introduction into the U.S., Bayer had received well over 600 incident reports, possibly close to 700 (Bayer’s reports to the US EPA were in poor condition and poorly documented, thus the EPA reviewers could only estimate the exact totals).

These reports included at least 70 deaths (17 dogs, 46 cats, 7 unspecified), 300 reports of skin irritation, 73 reports of central nervous system disturbances, including convulsions, 90 reports of lethargy, malaise, etc., and 92 reports of vomiting, diarrhea, or other gastrointestinal reactions. (Some animals had more than one reaction, but each animal was listed only one time in the above statistics.) . . . There are no short cuts without a price attached.”


The other camp
But as I intimated earlier, not all of our readers had a positive take on our articles. A few readers were outraged that we saw fit to describe the potential dangers of using spot-on pesticides, given that “so few dogs have actually died” following use of these products. Each of these people expressed their unwavering support of the companies and veterinarians who make and sell these products. One went so far as to suggest that he would not only continue to use the products, but would make it his mission to propagate negative information about the article whenever he could! Another wrote:


“Apparently you have twisted sound, scientific evidence and testing to make your article more interesting. Shame on you for not investigating your author’s so-called ‘facts.’ I happen to have a copy of the Material Safety Data Sheet from one of the products she accuses of being a health risk to humans and animals. You claim that Imidacloprid (the active ingredient in Advantage Flea Adulticide) causes thyroid lesions in dogs and that carcinogenicity is “yet to be determined,” when in fact, based upon the MSDS animal toxicity data, Imidacloprid is labeled as having no evidence of carcinogenicity and there is nothing written about thyroid lesions in dogs . . .

“I am a very concerned pet owner who takes impeccable care of her animals. Articles such as this are very hard to stomach and hopefully you will do the right thing and recant your false information. Granted, some products can be very dangerous to animals, but to include products such as Advantage and Frontline in the same category is just plain wrong. I have provided several of my friends with the article and hopefully you will be hearing from them, too; we are satisfied users of Advantage and trust our veterinarians’ advice.”


To which I can respond only that I did, in fact, personally witness the mounds of documentation that our author compiled in support of her article. It’s true that there are not easily accessible reports on the potential health effects of these products – but they do exist.

I also have seen how difficult it is to obtain information about pesticides in general and spot-on products in particular. Our author had to submit Freedom of Information Act requests to obtain access to the full results of the pesticide makers’ tests. It took some companies more than six months to respond to these requests (which they are legally required to respond to); some companies have not yet responded, nine months later.

The makers of these products are not unique. Like most pesticide manufacturers, they are in a race against time, and they have a vested interest in stalling.

There is a certain window of opportunity for all pesticide makers, in which their products can be aggressively marketed. The window opens when they have passed the EPA’s initial safety tests. The products are put into use in the consuming public – and then adverse effects reports begin to come in. As the number of these reports rises, the target of the pesticides begins to adapt and develop resistance to the poisons.

It may take years or even decades, but eventually, the window closes, when the products are no longer effective due to target-resistance and/or when the number of product injuries is so high that the EPA must finally file “stop action” orders against the chemical makers.

This is history, not speculation. In the past couple of decades alone, dozens of pesticides have been ordered out of existence for these reasons. This includes several flea-killing pesticides, including (most recently) chlorpyrifos (Dursban).

All of us take risks every day, and it’s up to us to weigh the risks and benefits of all of our actions for ourselves. In our articles, we are not judging you or the decisions you make for your dogs. We simply want to faciliate your ability to make informed decisions. You may well decide that the risk of injury to your dogs and your family is so small, it’s not worth worrying about. Others may decide it’s an unneccesary risk. Finally, here’s another aspect to consider:


“My reason for writing is to point out one more urgent reason not to use these toxic products. You didn’t explicitly confront the issue, but it was horrifyingly evident in the data presented: the products are tested on laboratory animals, including DOGS! The description of laboratory studies brought me to tears. What an obscene concept to torture and kill laboratory dogs in toxicological studies so that the manufacturers can assure us the products are ‘safe’ to use on our companion dogs. I hope other readers will take note and stop using them.”


What about ticks?
Some readers were disappointed that we did not discuss ticks and tick control methods in these articles. I’m sorry that I failed to direct readers to our last article on the subject, “Ticked Off,” August 2001 issue.

However, while fleas and ticks may be (to some extent) successfully treated with some of the same pesticides, the two types of insects pose very different dangers and control challenges to dog guardians. The habitat, feeding patterns, and life cycle of the tick is very different from that of the flea, and they are not nearly as easy to target with an integrated pest management (IPM) system as are fleas. In the August 2001 article, we do discuss the issue of balancing the dangers of tick-borne diseases against the dangers of pesticides, as well as mention some IPM methods for tick control.

Losing our nerve?
As I mentioned earlier, flea control seems to be an incredibly polarizing issue for most dog guardians, and the letters we received were, with one exception, either strongly supportive or strongly critical of our articles on pesticide use for fleas.

The one exception was when we both scored and bombed. This reader was initially thrilled that we “took on” the pesticide issue, but was also saddened that we offered suggestions for those who were not yet ready to give up their use of spot-on pesticides. In response to our suggestions for a “reductionistic” approach, she wrote:


“I just wrote you a letter praising you for your courage to publish the truth about topical flea killers. Then I accessed the latest issue online and couldn’t believe my eyes after reading, ‘Addicted to Spot-Ons?’

“How can you publish an article one month confirming that these products are comprised of known carcinogens, then the next month say ‘Well, if you have to use these products . . .”? This article seems like a concession to somebody, but I don’t know who. Are you worried about alienating the users of these products and thus losing their subscriptions? Shouldn’t you be more worried about alienating the subscribers who either don’t use these products and are grateful for the validation and/or the ones who were using them and will reconsider based on this new information?

This undermines the truth of the valuable message delivered in the February article. Please don’t abandon your stand once you’ve taken it.”


I’m sorry this is how the “at least, reduce your use” article appeared. Actually, it was an effort to offer some practical compromises – ones that would benefit dogs – to people who are adamant that they cannot control fleas without pesticides. We do strongly believe that dogs, humans, and the environment would be far better off with reduced, and better yet, zero toxic pesticide use.

As always, thanks for your close attention and support of WDJ.

–Nancy Kerns, Editor