Every dog owner knows that getting rid of fleas can be one of the biggest challenges of dog-keeping. Few people know, however, that the process can also be the most damaging to their dog’s health. Specifically, the use of insecticides on the dog and all around the dog’s environment can cause nerve and liver damage, impair the immune system, and even cause cancer. And you have to wonder – if these effects have been noted in dogs, what effects do all these toxins have on the people who live with the dogs?
It’s a real problem, because if you have fleas in your home, you have to do something. They can make your dog (and you and your family) miserable through their tiny but painful bites, as well as the allergic reactions that many people and dogs develop to flea saliva. They are prolific, producing thousands of eggs during their three- to four-month life-span. In ideal conditions the cycle takes just two weeks, from egg-laying to larvae to pupae to hatched fleas capable of laying eggs of their own.
The chemical approach to flea control can involve use of a panoply of toxic powders, shampoos, sprays, bombs, dips, and collars. Not incidentally, its probably the casual use and mixing of several of these products that can pose the biggest challenge to the dog’s health, as his body strives to deal with his exposure to several different types of toxins.
Toxic families
There are a few major types of chemicals most widely used in the war on fleas.
Organophosphates, most of which are readily absorbed through skin, eyes, stomach, and lungs, are among the most common pet insecticides and are responsible for the majority of pet poisonings. Initially, overexposure can result in salivation, involuntary defecation, urination, and vomiting. This can progress to ataxia (lack of balance), convulsions, teary eyes, slow heartbeat, and labored breathing.
Carbamates are the second-most common compound in flea-control products. The effects of exposure to carbamates are generally less severe than organophosphates, and carbamates do not accumulate in the tissues. Dogs who are overexposed to carbamates will exhibit many of the same symptoms of poisoning as the organophosphate-poisoned dogs. Long-term, the chemicals can cause lowered production of bone marrow and degeneration of the brain.
Organochlorines, a third major class of insecticides, are not as immediately toxic as the first two, but do accumulate in the tissues and persist in the environment for years. (DDT, an organochlorine, was banned in 1972 but is still found in 55 percent of Americans.) Poisoning with this chemical may stimulate the dog to exhibit exaggerated responses to light, touch, and sound. Spasms or tremors can progress to seizures and death. Yet another class of flea-killing chemicals, pyrethrins, are often labeled as “natural,” due to the source of the poison: the chrysanthemum flower. But despite their origins, pyrethrins are still potentially dangerous, and have caused allergic dermatitis as well as systemic allergic reactions, vomiting, headaches and other nervous system disturbances.
How toxic are these pesticides?
An estimated 20,000 people receive emergency care annually for actual or suspected pesticide poisoning, and approximately 10 percent of these are admitted to the hospital. Each year, 20-40 people die of acute pesticide poisoning in the U.S. Also in the United States, most episodes of acute occupational poisoning are due to organophosphate and carbamate insecticide exposure. And there’s no telling how many animals succumb to pesticide poisoning.
Each of the chemicals mentioned above are intended to kill fleas via direct contact. In recent years, the focus of development of flea-killing chemicals has been on substances that affect only the fleas that actually bite a treated dog. These substances, which are either applied to or fed to a dog, are intended to linger in the dog’s body without affecting his own chemistry, waiting to deliver a fatal blow to any flea that drinks his blood. While these chemicals are proving to be far less harmful than the older flea-killing substances, and conventional veterinarians enthusiastically encourage their use, many holistic practitioners are less enthusiastic about the drugs. (See “Should You Get With the Program?”)
Natural flea control
Fortunately, there are many natural, effective methods of controlling fleas widely recommended by both conventional and holistic veterinarians. The most successful approach will utilize several indoor and outdoor methods. A pesticide-free battle takes a little more time to win than one that utilizes deadly foggers and shampoos, but it has the advantage of not killing your dog. Regular flea-combing is the most direct and low-tech method, and it works as a good flea-population monitor, too. Pet supply stores sell the fine-toothed combs that pull fleas through the fur and trap them. The comb is then dipped in warm soapy water to remove and kill the fleas.
Since fleas spend only a portion of their time on the dog, and eggs, larvae and pupae, are likely to be found in any area where the dog lives, most of your flea-eradication efforts should concentrate on your home and yard. This may not be welcome news, but the safest way to get rid of fleas is through fastidious housekeeping.
The length of the flea’s life depends on environmental conditions, but it can live out its entire cycle in as little as three weeks or as much as six months. Female fleas are prolific, laying as many as 20 to 50 eggs per day for as much as three months. Development of the larvae that hatch out of the eggs takes place off the dog, usually on or near the dog’s bedding and resting areas. Concentrating your efforts on removing the opportunities for the eggs to develop is the most effective population control strategies.
One way to remove the eggs’ opportunities to develop is to remove the eggs, and to this end, your vacuum will be one of your most valuable tools in the flea war. Vacuum all the areas that your pet uses frequently, at least every two to three days. Since fleas locate their hosts by tracing the vibration caused by footsteps, vacuuming the most highly-trafficked hallways and paths in your house will be rewarding. Don’t forget to vacuum underneath cushions on the couches or chairs your dog sleeps on. Change vacuum bags frequently, and seal the bag’s contents safely in a plastic bag before disposing. Some people place flea collars in their vacuum bags, to kill any fleas or flea larvae they vacuum up; this is probably the safest application for the toxic plastics.
The dirt on dust
Some people use diatomaceous earth (also known as DE or Diatom Dust), a non-toxic powder more commonly used in swimming pool filters and as a garden soil amendment (the latter kind is the form used against fleas). The powder acts as a powerful desiccant on the waxy coating that covers fleas, technically dehydrating them to death. It also kills flea larvae. DE can be sprinkled onto carpets and swept across wood floors (so it works into the cracks in the wood).
A couple of cautions: because it consists of tiny, hard particles, it can contribute significantly to wearing down your carpets, and some carpet manufacturers’ warranties won’t insure the carpet if you use a desiccant powder. Also, neither you nor your dog should inhale the powder, which can physically (rather than chemically) damage the lungs. Use a dust respirator when applying.
There are a number of powders and sprays that utilize pungent herbs or essential oils intended to drive fleas away. Eucalyptus is a common ingredient, as is peppermint. But unless these products are used in an overwhelming concentration, or in combination with other remedies, they are unlikely to be effective.
If your dog habitually sleeps in one or two areas, or has a bed, cover those spots with a towel or a small, washable blanket. Immersion in water kills both eggs and developing flea larvae, so wash the bedding every other day or so. Some people keep two or three sets of towels for bedding so the dog’s favorite spot is always covered – keeping the trap set constantly, as it were, for flea eggs.
Wash uncarpeted floors at least once a week. Wood floors are especially important to wash well, since the larvae tend to burrow into cracks in the wood. Similarly, steam cleaners (used without chemicals) can kill flea eggs and larvae present in short carpets. You probably couldn’t (or wouldn’t want to) get thick rugs wet enough to kill the eggs, however.
Taking the war outside
Outdoors, it’s easier to use water to your advantage. Most dogs pick out a couple of spots in shady or protected areas where they spend most of their time in your yard. Fleas, too, like these shady spots; in fact, neither the adult fleas nor the larvae can survive very long in direct sunlight. It’s unnecessary, then, to worry about the lion’s share of the landscaping or lawn areas around your house. At least once a week, wash down the areas your dog uses for sleeping and resting.
Other safe tools you can use in the outdoor flea war are beneficial nematodes, tiny creatures that seek out and kill fleas. Several companies raise and sell the nematodes, which are strictly insectivorous and cannot harm humans, pets, plants, or the beneficial earthworms in your garden. Application of the nematodes is simple. About one million nematodes come packaged on a small sponge pad, about 2-3 inches square. The sponge is soaked in about a gallon of water, and then the water is sprayed over the area to be treated. The nematodes should be distributed at night or on a cloudy day, since they die if exposed to direct sunlight. They also work best in a moist environment, so watering the yard well for several weeks after application helps them do their job most efficiently.
Nematode sources include The Bug Store, (800) 455-2847, and Integrated Biocontrol Systems, Inc., (888) 793-IBCS. Both sources offer can take your order over the phone with a credit card, and provide overnight shipping. These companies suggest using about one million nematodes per every 2500 square feet of garden or yard. Does this sound like a lot? Don’t worry! Costs range between $1-15 per million, depending on the source and quantity purchased.
-By Nancy Kerns
