The Wrong Flea/Tick Medicine Can Kill Your Pet

In the northern part of the country this is the time of year when pet clinics start seeing more and more patients with flea and tick infestations as well as Lyme disease infections and the even more dangerous heart worm attacks. Heart Worm causes congestive heart failure and often can’t even be treated – it must be prevented. Flea and tick medicine can do that.

No responsible pet owner wants their animal to suffer needlessly and anyone with a house pet certainly doesn’t want their dog or cat to bring fleas and ticks into their home, vehicle, or most embarrassing, into other people’s homes on a visit.

For years people have seen TV ads and store displays offering medicate-it-yourself drops you can put on your pet’s neck and back.

Many pet owners have also heard horror stories about the use of these spot-on flea and tick products causing illness or even the death of the pet they were supposed to protect.

Now the U.S. EPA and Health Canada are investigating these reports and considering stricter regulations.

See below for more information on these over-the-counter medications but I wanted to begin with what appears to be a highly safe and effective medication so pet owners know that not everything is bad.

While TV news has been reporting the possible problems, they have not been telling consumers about safer specific prescription medications which are available.

But some flee, tick, and heartworm prevention products are considered safe and I checked with a well-known local veterinarian to see what he used and why. Unsurprisingly, he recommended Revolution, the same medicine he prescribes for his patients and uses on his own pets.

Here is what Dr. Blais, a graduate of Penn State and the University of Pennsylvania School of Veterinary Medicine had to say exclusively to about Topical Parasite Prevention In Dogs and Cats.

“In 2008, 44,000 potential toxicities associated with the use of topical parasite prevention products were reported to the EPA. In my practice, Blais Veterinary Hospital, 107 Blais Road, Indiana, PA, four cats were treated for convulsions last summer their owners reported they used Spot On.

Since 2000, every summer has caused some client’s poisoned animal to require hospitalization in our Clinic. Most go home alive, some don’t.

All of the animals hospitalized at Blais Veterinary Hospital have been treated with over the counter preparation Spot On or Hartz products seem to predominate. No animals have been hospitalized after using Advantix, Frontline, Frontline Plus, or Revolution.

In most cases I recommend Revolution for my client’s cats and dogs. It does a good job for flea and ear mite prevention. I’ve successfully treated scabies with the product and it is as good as the others for ticks and it prevents heartworms.

I’ve only seen a few heartworm positive over the years, but the treatment for heartworm is not safe. Left untreated most dogs drift into congestive heart failure. Arsenic is the active ingredient in the treatment available. Most of the dogs I’ve treated did well but I remember a little Boston from Connecticut that died from liver failure caused by the arsenic and cats can’t be treated at all.

My view is better safe than sorry. Reactions to Revolution in my practice after tens of thousands of doses have been very few and mild loose bowel for a day or irritated skin rashes where the product was applied. Flea bite dermatitis in dogs and cats is now rare and the number of Zepps or ear ablations I’ve done in the last ten years of practice is zero. Outside hunting cats are now free of intestinal parasites and I presume so are their owners.

“I couldn’t recommend another product that is as effective with so few side effects. I use Revolution on both my cat and dog.” – Douglas R. Blais, VMD.

Of course the pet supply companies are fighting back and the original list of products being investigated has apparently been modified now to include all EPA listed products, not just the ones originally targeted for investigation.

On April 20, 2009, the EPA released a document titled “Increased Scrutiny of Flea and Tick Control Products for Pets. (

The original list included these major products and brands: Hartz Mountain, Zodiac, Farnam (Adams), Sergents, and TradeWinds.

The new list (May 15, 2009) is many pages longer and now includes “all” EPA registered/listed products.

It is, of course, up to the reader and pet owner to make up your own mind as to which list (the original one of “those being targeted” by the EPA for investigation, or the replacement list of “all” available products) is most informative and why any changes might have been made.

The EPA has a pet safety page at

As with any medical advice, Dr. Blais stressed to that pet owners should visit their own veterinarian for specific advice and prescriptions best for their particular pet.