Carlos ActivylThat insufferable scratching…

Is your pet’s itching driving you crazy? If so, you’re not alone! “Flea season” is upon us and it has come with a vengeance this year.

But wait! My pet can’t have fleas- I use flea treatments regularly to take care of that problem.

Unfortunately, in our practice, we’ve been noticing a marked rise in flea resistance to many of the popular spot-on flea treatments recently, especially to drugs like fipronil. In other words, you, the pet owner, are doing everything right by applying your flea prevention regularly, but it’s not killing the fleas as effectively anymore. The result: utter frustration (and itchiness).

What’s changed?

The short answer is the fleas themselves. Over time, fleas exposed to a certain chemical become resistant to that drug. That 99.9% effective advertised kill rate was true initially, but that left the 0.1% of fleas that it did not kill to breed the next generation of “super-fleas”. The end result over many years of selecting for resistant fleas is now the majority of the population is resistant, rather than just a fraction…

The bottom line: The popular flea products are not working as well anymore, just as they are gaining brand recognition amongst pet owners.

What to do about it?

Just because one flea product may not as effective at this point in time does NOT mean that you should skip your monthly flea prevention! So far, this resistance to certain products has been regional, meaning certain areas of the state one brand of flea prevention is still effective, while it does absolutely nothing in another area. With so many brands available, it can be difficult to sort out what will be most effective for your pet.


Consult your veterinarian for the best flea prevention in your area. It may be one of the “tried and true” brands, but newer products such as Activyl and Bravecto, are available and may be better options.

The goal remains the same; give your pet relief from flea bites and you the peace of mind of knowing that your pet and your home is not (and will not) become infested! It is far more difficult to clean up a flea infestation than to prevent it- take it from someone who sees this on a daily basis!