The Old Trainer: Beware mainstream flea medication

May 16, 2013 

Dear Old Trainer: We adopted Hulk, a Rottweiler, last fall, so this is the first year we have to worry about ticks and fleas. Hulk has already gotten several fleas, but no ticks yet. What flea products do you use on your dogs and do they work?

— Charley,Wichita, Kan.

A: I tried every mainstream flea product on the market, Charley. They all work, but I will never use them again because all but one contain chemicals so toxic it is dangerous for humans even to apply them to pets.

One popular liquid product warns, "If product gets on your skin, rinse with soap and water for 20 minutes, then contact your local poison control center."

The products contain carcinogens — meaning they cause cancer in humans — yet are designed to be applied to the skin of our pets. They are then absorbed into the bloodstream, brain, organs and fur.

The products warn that cats or dogs may die if they lick the fur of the treated dog.

If the fur of a dog can kill another dog or a cat on contact what is it doing to the treated dogs? And what effect do the carcinogens have on the family petting them and handling them day after day?

There is no long-term research available, so I did my own investigation and was shocked by what I found. I now refuse to buy products that contain any of the following chemicals: imidacloprid, fipronil, permethrin, methoprene, pyriproxyfen, carbaryl and propoxur. All are listed as carcinogens by the EPA.

But fleas themselves may cause serious illness if untreated, so how do we protect our dogs?

I choose to fight the pests with products that are natural and contain no toxins. It is a two-stage approach.

I use the one flea product — Comfortis — that is effective but contains no toxic chemicals. It is given orally and appears to have no side effects. The ingredient that kills fleas is spinosad, rated a natural product by the EPA.

It works with my dogs, and the only negative aspect I found are some accounts of dog owners reporting adverse reactions when Comfortis is combined with products containing ivermectin.

Heartworm pills contain ivermectin, but the makers of Comfortis claim the amount is too small to cause problems, that adverse reactions occur only when using the large amounts required to treat mange and other diseases.

I play it safe by not buying any product containing ivermectin while I use Comfortis.

The other stage is generous use of Diatomaceous Earth, a nontoxic natural powder, which kills both fleas and their eggs. Sprinkle it on rugs, floors, and dog's bedding, then vacuum it up after a few days and you won't have fleas in your house.

Apply it directly to the dog if you find an area infected with fleas. It is cheap, about $5 a pound, but make sure you get the "food grade" level, not the type used in swimming pool filters.

Next week I will share my findings on how to deal with ticks, lice, heartworm and other pests.

Jack Haskins writes as The Old Trainer. A trainer for more than 30 years, he has rescued, trained and placed more than 2,000 dogs. Send questions for The Old Trainer to

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