The Dangers of Flea Spray

Dangerous Chemicals

• Many flea and tick preventives contain pesticides and insecticides that can make pets ill. The U.S. Environmental Protection Agency classifies synthetic neurotoxins including pyrethroids, organophosphates and carbamates, all found in flea treatments, as potential cancer causers in humans. Pyrethroid concentrations in some flea-control products are nearly 20 times stronger than levels allowed for use on humans. Organophosphates and carbamates can affect the nervous system in animals. Cats are especially vulnerable to organophosphates because they lack enzymes that metabolize the chemicals. As of September 2010, a carbamate-based substance called carbaryl is banned from new flea preventives, but pet-supply stores can sell existing products containing carbaryl. Check labels carefully and avoid products with carbaryl. Other neurotoxins used in flea preventives include etofenprox and imidacloprid.

Symptoms of Poisoning

• The neurotoxins in flea preventives target nerve cells, muscles and brain tissue in pets. Some side effects of flea-preventive toxicity include hyperactivity, excessive salivating, dilated pupils, tremors, vomiting, diarrhea, hiding, shivering and skin irritation. Open sores on the skin where you applied spot treatments could emerge as well. More serious symptoms might include breathing difficulties, brain damage, heart attacks and violent seizures that could result in death. Afflicted pets might lose their appetite for food and water, and kidney failure could also occur.

Official Response

• Makers of flea preventives say fewer than 1 percent of sales result in poisonings as long as pet owners follow application directions. Representatives of the American Veterinary Medical Association also say harmful reactions are rare if owners apply flea preventives according to instructions. But some independent vets and environmental advocates have called on manufacturers to pull neurotoxin-containing flea treatments from stores. The Center for Public Integrity released a study in 2008 reporting at least 1,600 pet deaths related to spot preventives with pyrethroids in a five-year period. The EPA reported more than 25,000 reports of pet-pesticide reactions from 2003 to 2008, though it also cautioned that it didn't verify the reports' authenticity. The EPA continues to study the safety of neurotoxins in flea preventives, but federal law doesn't require manufacturers to test treatments before marketing them.

Prevention

• Consult with your pet's veterinarian and read product instructions carefully before applying flea and tick treatments. Never use dog-designated treatments on cats, or you could cause a fatal overdose. Don't use half of a large dog's dose on a smaller dog, and don't double a smaller dog's dose for a larger animal. Avoid applying flea and tick treatments to older or pregnant pets, and separate your pets after applying the treatments. Animals will often lick flea and tick preventives off of each other's fur, and become sick in the process.

Alternatives

• If you want to avoid the pesticides in conventional flea control, stop by a store specializing in natural foods and other products for pets. Look for shampoos, collars and other preventives containing less-harmful substances such as neem tree oil or the citrus byproduct d-limonene. Herbal flea powders with eucalyptus, rosemary, fennel and wormwood can also be effective for some pets. Brewer's yeast, given either as an oral supplement or rubbed on your pet's coat, may also help control fleas and ticks. Keep your pets inside during heavy flea season in the spring, and consider consulting an exterminator to eliminate fleas in your yard, before they can enter your home and infest your pet.