As a dog owner, keeping my dog clean and free of ticks and fleas can sometimes seem like a real chore. Over the years I have tried a few different methods in controlling fleas and ticks. Though I never used a flea collar, I have tried the shampoos and the treatments that you apply down the back of the dog. A few years ago, I stopped using both of these things, particularly after actually reading up on some of the chemicals that these products contain, mainly insecticides. (Though when a bottle of shampoo has to have a disclaimer about being toxic to aquatic life, I should have taken that as a bad sign.) Beyond potential issues with your pet's health, they can also have an adverse effect on some people.

The active ingredient in most modern tick and flea shampoos is commonly a pyrethroid, a class of organic compounds related to natural pyrethrins found in some flowers. Most household insecticides stem from this class of chemicals. The problem with many of these is that, quiet bluntly, they are toxic. Most have labels that state as much, particularly with regard to animals and aquatic life. Pyrethroids are considered safe for vertebrates since they have the enzymes and biology in place to break down these chemicals in fairly short order.

Except for cats... Ostensibly, dogs and humans can break down these insecticides in the liver in kidneys without long term effects. Because cats cannot breakdown a common pyrethroid used in flea and tick treatments, phenothrin was pulled by most manufacturers in 2006. Adverse reactions ranging from tremors and hair loss to salivation and death were reported when used with cats.

Cats notwithstanding, most pets and humans are fairly safe when using products that contain pyrethrins. Be even if these products are relatively safe for use around humans and dogs, there are still other compounds found in these can produce adverse reactions in people and pets alike.

D-Limonene (smells like oranges and sound innocuous enough, right?) is assumed to be the culprit in a case where a Pomeranian in Washington recently suffered a severe allergic reaction. The family pet developed edema throughout her body but ultimately recovered. Limonene is also used as a solvent in cleaners, air fresheners, and even glues. While D-Limonene is used commonly used in cosmetics and as an insecticide, the FDA recommends against using this hydrocarbon on cats or dogs, and some with sensitivities may develop contact dermatitis or a general sensitivity to the compound.

In another instance where chemicals in flea and tick repellents more directly impacted a person, a pet shampoo distributed by Sogeval Laboratories, Inc., with an ingredient, phytosphingosine, was associated with the death of one woman who was bathing her dog with the product. An acute asthma attack was the cause of death, and just a few days later, another asthmatic family member suffered a mild asthma attack while bathing the pet with the same product. The belief is that the particular substances used in that formulation of pet shampoo triggered the two asthma attacks in the individuals involved.

This is not to say that all pet shampoos are going to cause problem for you or your pets, but what it does highlight is two things. First, read labels. If there's something you're unfamiliar with, look for a known alternative. When you do come across an unknown compound, check online for the MSDS sheet or visit the manufacturer's website to get as much information as you can. You can then search for these compounds to find out more about them and potential hazards. This may seem like a lot, but it literally takes 10-20 minutes of searching online. Second, some ingredients in flea and tick treatments, as well as cosmetics, cleaners, and other household products, can react differently with different people (particularly those who have an existing allergic or asthmatic condition and those who have shown a sensitivity to chemicals that don't affect most others).

As a side note, for fleas and ticks, I use the Ecology Works pet shampoo. Personally, I like the smell, it lathers well, and I've yet to find a flea or tick on my dog (despite my roommates dog having fleas a couple times since we have lived together.

Author: Kevin G.