Question: "You've written before about the dangers of using chemical flea-control products. I've used spot-on products for years for my dog. He's never had any fleas and has never gotten sick from the flea medicines. What proof do you have that these flea products are harmful? It seems to me that you're just trying to scare people to stop using medicines in favor of alternative therapies."
Answer: That's a great question. A better question that I would ask is, "What proof do you have that these products are safe?" The answer, of course, is that we have no proof these products are safe for long-term use. Why not? Because the EPA, which registers insecticides, does not require long-term safety testing. In most cases, the active ingredient is tested for a period of time (13 to 52 weeks) for acute toxicity in normal, healthy, adult laboratory animals. The inert ingredients, which are company secret formulas and which may be more toxic than the active ingredients, do not require this same amount of testing. We know that all of the active ingredients in these flea products, which are toxins to the nervous system, cause a whole range of side effects, including cancer and diseases of the liver, kidneys and immune system. Additionally, long-term use of these chemicals can have an additive effect. Our pets are exposed to enough chemicals in their food, vaccines, medications and city pollution. We don't need to add to their toxic load by using unnecessary insecticides.
Flea chemicals can also have a synergistic effect, which means their toxicity increases as additional chemicals are applied to the pet (most pet owners use more than one flea chemical at a time). Do you find it interesting that these products are applied to the skin of your dog, yet the labels warn not to get any of the stuff on your skin, and to wash it off immediately if you do get it on yourself?
While I am not opposed to the occasional, short-term use of chemical flea products if absolutely needed, I prefer a more organic approach using safer products. Many of my new clients are using the chemical products on a regular basis. When I ask them why, they reply that the products were prescribed by their prior doctors. Yet these pets are rarely outside, and the owners have never seen fleas on their pets. Simply put, these are not the pets most likely to need regular flea control. Our first goal is to take the pets off of these chemicals, which saves the owner a large amount of money and reduces toxicity to the pet. While it's true that good studies showing long-term harm are lacking, common sense tells me that long-term use of any nerve-toxic chemical cannot do the pet any good.
Shawn Messonnier, D.V.M.
Shawn Messonnier, D.V.M., is a holistic veterinarian and nationally recognized expert on integrative medicine for animals. He is the author of several books, including The Allergy Solution for Dogs, The Arthritis Solution for Dogs and the award-winning Natural Health Bible for Dogs and Cats.