Each year, Americans purchase and apply to their pets a vast array of toxic chemicals intended to kill fleas and ticks. These include collars, sprays, dusts and more. Other pet owners take their pets to veterinarians to be dipped in chemicals. Many consumers probably assume that the products they and their vets use have been subjected to rigorous testing, and must, by virtue of their very ubiquity, be safe. After all, how could the government let deadly poisons be sold on grocery store shelves without applying stringent standards?

The simple truth, however, is that the poisons in many of these products are not safe, either for pets or humans. Government regulation of these products has been sketchy, and testing of their impact in the home has been inadequate. The result is that many of the products sold by the millions in grocery, drug and pet supply stores, even when applied as instructed on the box, can cause serious health consequences to pets and humans.

The main culprits are products that rely on a family of chemicals called organophosphates. Seven of these are in common use in pet products: chlorpyrifos, dichlorvos, phosmet, naled, tetrachlorvinphos, diazinon and malathion*. They are used in brands marketed under a variety of names, including Alco, Americare, Beaphar, Double Duty, Ford’s, Freedom Five, Happy Jack, Hartz, Hopkins, Kill-Ko, Protection, Rabon, Riverdale, Sergeant, Unicorn, Vet-Kem, Victory and Zema. Another family of chemicals, called carbamates, is also of potential concern. The two most common carbamate chemicals used in pet products are called carbaryl and propoxur.

 *NOTE FROM THE NPA: Malathion is also used in a particular prescription head lice treatment marketed as Ovide®

Organophosphates and carbamates work by interfering with the transmission of nerve signals. Since the chemical process they attack is common to insects, humans, dogs and cats, they harm more than just fleas and ticks. Indeed, thousands of acute toxic poisonings have been logged at poison control centers across the United States. Moreover, ample evidence suggests the possibility of worrisome long-term effects for children exposed to these products at an early age, including later-in-life cancer and perhaps Parkinson’s disease.

Children, and particularly toddlers, are especially vulnerable for two reasons. First, their nervous systems are still developing, so the violence done by organophosphates can do greater and more lasting damage. Second, children’s normal behavior brings them in close contact with their pets, and therefore to any poisons applied to those pets. In particular, toddlers’ hand-to-mouth tendencies make it easy for toxics to be ingested, and not just by petting the family dog and then putting their hands in their mouths. Because children spend their time where the toxics from pet products tend to accumulate -- crawling on rugs, playing with pet toys, handling accumulations of household dust, and more -- they are likely to come in contact with these poisons even when they do not touch their pet.

As bad as these products may be for pet owners and caregivers, they often are worse for the pets themselves. Based on the very limited data available, it appears that hundreds and probably thousands of pets have been injured or killed through exposure to pet products containing pesticides. As with small children, pets cannot report when they’re being poisoned at low doses.

Healthier alternatives to these pesticides are readily available. Easy physical measures like frequent bathing and combing of pets can make the use of pesticides unnecessary. Pet products containing insect growth inhibitors also can stop fleas from maturing and reproducing successfully. In addition, newer insecticides, sprayed or spotted onto pets, have been developed that are effective against fleas and ticks without being toxic to the human nervous system. The safety and effectiveness of these alternatives makes the continued use of older, more toxic pet products tragically unnecessary.

The threat posed to humans and pets by the poisons in commonly available products is intolerable and unnecessary. With that in mind, the Natural Resources Defense Council has called on retailers to remove organophosphate products from their shelves, and has called on the EPA to immediately ban the use of organophosphate pet pesticides. NRDC has also asked the EPA to consider banning pet products containing carbamates, and to take steps to better inform veterinarians, pet owners and the general public about safer alternatives for the control of fleas and ticks on pets.

What Pet Owners Can Do

In the meantime, pet owners can protect their families and their pets with some simple steps.

First, pet owners should begin using safer products on their pets, avoiding organophosphate-based products. Specifically, consumers should avoid products that list chlorpyrifos, dichlorvos, phosmet, naled, tetrachlorvinphos, diazinon or malathion as active ingredients. Pet owners should also avoid carbaryl and propoxur. In many cases, fleas and ticks can be controlled with simple physical measures, such as brushing pets regularly with a flea comb while inspecting for fleas, vacuuming, and mowing frequently in areas where pets spend the most time outdoors. In other cases, these physical measures may be combined with pet products that use "insect growth regulators," or IGRs. (But be careful to avoid products that combine both insect growth regulators and organophosphates.) If those steps don’t suffice, or if your pet is allergic to fleas and needs immediate relief, two newer pesticide products can be sprayed or spotted onto pets: fipronil (marketed as Frontline* or Topspot™) or imidacloprid (marketed as Advantage*).

In particular, pregnant women and families with children should stop using organophosphate- or carbamate-based products immediately. Finally, children should never be allowed to apply flea shampoos, dusts, dips, etc. containing organophosphates or carbamates to their pets. The unfortunate truth is that the EPA has overlooked and underestimated the particular risks to children when evaluating the safety of these products for home use.

Based on Poisons on Pets: Health Hazards from Flea and Tick Products, a November 2000 report by the Natural Resources Defense Council.