The never-ending battle against fleas

Dr. Jody Kaufman

As the summer starts winding down, fleas start ramping up their assault. Years ago it was a never-ending battle to control them. People would spray, dip, bomb the house, and repeat the cycle all over again until winter came to the rescue. Then, almost twenty years ago, everything changed with the arrival of the spot-on medications. Advantage and Frontline were the first. It seemed like a miracle! For the first time, dogs and cats weren't plagued for months once they encountered fleas.

Then last summer something changed. We normally see one or two animals a week in the late summer who are suffering from fleas, and they are usually pets who have not been on a prevention program. We started seeing 5-6 each day, many whose owners had been diligent in their attempts to control the situation.

So what caused the population explosion? Certainly our summers have started a little earlier for the last couple of years. But we had been getting reports from the Southern states as well, suggesting that fleas were becoming resistant to some of the prevention medications. The evolutionary trend finally reached New England. Flea biology changed enough that some of the compounds were no longer effective. Many of the generics were no longer working, but we also observed many failures with Frontline.

Once the fleas have established residency, treating the animal with topicals is no longer adequate to control them. It's necessary to address the whole flea life cycle. This requires treating the environment as well as using growth regulator compounds that inhibit flea reproduction.

There are a host of medications on the market, some more effective than others. An oral medication called Comfortis is quite effective. It is also available combined with the heart worm preventive Interceptor in a preparation called Trifexis. Unfortunately, it doesn't address the tick problem.

This year is not as bad as 2011 was for fleas, but we are still seeing more than in past years. The important things to remember are:

  • Be diligent about flea control. Start before you see fleas (June is best) and continue until the ground is truly frozen (November or December).
  • Use a flea comb and stay alert for any infestations. Be aggressive about getting rid of them once they're in your environment.