My Toxic Dog: Personal Experiences with Flea Collars
Posted April 23, 2009
When my team at NRDC decided to study whether flea collars leave a hazardous residue on cats and dogs, we really didn't know if there was a problem. It seemed possible that we wouldn't find much, and that the residues would be far below levels of health concern -- after all, that's what the Environmental Protection Agency had concluded on several occasions. Yet we weren't satisfied with the EPA conclusions. Even a cursory review of the basis for EPA's decision revealed major flaws, not the least of which was the complete absence of any actual data on residues from flea collars. Obviously someone needed to collect some real data to figure this out.
I volunteered my dogs, Kanga and Cricket, as participants in the study. After all, with no young kids at home, it was free flea control (which meant no baths for the dogs) and an ability to collect some useful information. The negatives started to appear soon after the flea collars went on. First of all, the collars had a nasty odor, so the house began to smell; friends who visited sniffed distastefully, and some even commented. A noticeable powder bloomed on the surface of the collar, and sometimes a little was visible on the fur. Although the dogs didn't seem to notice the collars, I began to get concerned. The package directions advise avoiding direct contact with the collar. So each day I'd go through contortions to put their leashes on and take them off, and would grab for their leather collars to restrain them only to discover that I had the flea collar clenched in my hand instead. I washed my hands frequently, like I do when I'm working in the hospital, and the poor dogs begged for attention while I refrained from petting them. My partner bore with the entire procedure gamely until Cricket began scratching: "The dog has fleas! Damn it, I thought you said this collar would prevent fleas." Over the two week study, both dogs developed nasty cases of fleas - on their rumps, since the fleas wisely seemed to avoid the neck and back area.
It was such a relief when the experiment was over and we could give the dogs a good bath, wash their bedding, and rid ourselves of both the fleas and the chemical stench all in one frenzied cleaning session.
But the real problem was yet to come.
The results came back from the laboratory showing residue levels so high that the lab repeated the tests to be sure there was no error. There wasn't. When we plugged the numbers into standard risk assessment calculations, we had to stop and calculate again just to be sure.
The results were worrisome. After three days, half of the pets wearing collars with tetrachlorvinphos had enough residue on their fur to pose significant neurological risks for toddlers who spend about two hours per day with their pet. For toddlers who sleep with their pets, or have multiple pets, 80 percent of the dogs and all of the cats had residue that exceeded acceptable levels. The numbers for propoxur flea collars were even worse: all of the dogs (including mine) had residues on fur posing a neurological risk to toddlers. After two weeks, three-quarters of the pets had levels that exceeded the acceptable amount for average contact with a pet, and all of them had residue levels that could be dangerous for children with a lot of contact.
As if neurological harm wasn't enough, we also calculated the cancer risks. Cancer risk calculations assume that people are regular users of these products for most of their lifetime. For adults we found a cancer risk of 56 to 558 excess cancers per million people exposed -- 50 to 500 times greater than what the EPA considers acceptable. When we used EPA guidelines to calculate the increased risks associated with exposures in children, cancer risk soared to 157 to 1,566 excess cancers per million. That's potentially as high as 1-2 cancers per thousand people exposed - and there are a lot of pet owners out there who use these products, which equals a lot of risk to a lot of people.
The full story on the results of our flea collar testing is here.
The good news in this whole sobering story is that it's so easy to control fleas without resorting to any of these toxic products. My family has had dogs for 14 years, and we easily keep fleas in check with baths every 2-3 weeks, laundering their bedding at bath time, and vacuuming the rugs weekly. It's really not a big deal, and as a bonus, the dogs aren't greasy and they smell nice.
For other flea control tips, or for information about flea control treatments, check out Green Paws.