With spring temperatures rising also comes the rise of little springy things called fleas. Flea shampoos are often used to control fleas but a recent study[1] has found that mothers of autistic children were twice as likely to have washed their pet dog with pyrethrin containing anti-flea shampoo during the months prior to delivery.

Of course these findings only demonstrates a correlation, they do not prove a cause. Pyrethrins are naturally occurring compounds that are derived from Chrysanthemums. Pyrethroids are the synthetic version. They are both neurotoxins that over excite nerve cells and cause death in insects. Be careful if you use them. While they are toxic to pest insects, they are also toxic to fish and tadpoles and beneficial insects like bees. But, because they work well and are low in toxicity to humans, birds and mammals they are have largely replaced other pesticides like organophosphones for flea control.

They rapidly break down outdoors in sunlight, which is another favorable quality of pyrethrins. But, they can persist indoors on floors and carpets and on the coats of indoor pets treated with pyrethrin containing flea shampoos. This increases human exposure to this chemical and could explain why household pyrethrin use is correlated to increased findings of autism spectrum disorder.

What to do?

Of course, no one wants to suffer a flea infestation or see ones pets suffering. There are natural alternatives to pyrethrins. One such alternative is to kill the fleas before they get in the house. This can be accomplished by using beneficial nematodes. These are microscopic little round worms that feed off of fleas, grubs, cutworms and other garden pests.

Mr. Julian Biller of the Master Gardener program of the Buncombe County Cooperative Extension says that they are available through the Internet, “If you Google ‘beneficial nematodes’ you will be amazed at how many places there are where you can order them online.” He also said that they were available locally from Asheville Agricultural Systems, 45 Banks Ave., 253-4112. They will order them fresh because they are live organisms that must be kept refrigerated until used.

Be sure to follow the recommended procedures for best results. The outdoor conditions must be right. As opposed to just spraying a lot of chemicals around, one will need to take a little more care when applying nematodes to the lawn and garden.

Also, check the pet’s bedding. Most fleas are hiding in the pets environment. For each flea one finds in the fur there may be 30 fleas in your home. Keep the bedding clean

Be careful of “natural” flea treatments. They may be natural but harmful to your pet. D'Limonene, a derivative of natural citrus peels and found in many natural anti-flea products, can be highly toxic to cats. Other essential oils may cause problems especially to cats. There are some reports that cats’ systems are unable to break the oils down properly. Other reports, however, say that the purity of the oils is the problem. If one uses any product that causes persistent scratching, red or irritated skin or hair loss, discontinue the treatment and wash the effected area with soap to remove any remaining oils. If problems persist see your veterinarian.

For further advice on natural alternatives for flea control check out the following web site:
http://www.eartheasy.com/article_natural_flea_control.htm

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[1] 7th Annual International Meeting for Autism Research: Oral Presentation 113.4; Invited Educational Symposium 140.5. May 15-17, 2008.