Are Topical Flea Preventatives Losing Their Effectiveness?

There are several types of topical flea preventatives on the market today, with a few of the most popular being the various versions of Frontline (Frontline Gold, Frontline Plus, etc.) and the K9 Advantix line. While these topical flea preventatives have been known to be effective for years, there have increasingly been reports of them losing effectiveness in the last few years. I’ve used Frontline for years, partly because they’ve been so effective in the past. For at least the last decade I’ve used topical flea treatments on both our dog Soldier and our cat Peanut Butter and had excellent results with no side effects. All that changed this year.

A Flea Infestation

I’m a stickler for making sure we don’t apply any topical flea and tick preventatives too early (it could make my pets sick) or too late (the effectiveness diminishes over time). So a few weeks ago, I applied Frontline to Soldier and Peanut Butter both.  A week later, I took Soldier to his favorite groomer. I was shocked when, upon picking him up, the groomer said she’d had to give Soldier a flea bath because he had several fleas. I took him home and watched him carefully, using a flea comb to check him. I also washed all the bedding in the house, the dog bed, the cat bed, and the cat (Peanut Butter was NOT happy). Within just a few days, the fleas were back. It was obvious the topical flea preventative I gave Soldier wasn’t working, so I gave him another flea bath and took him to the veterinarian’s office a few days later.

Why Some Brands of Topical Flea Preventative Aren’t Working

At the vet’s office, they asked what product I used and told them it was Frontline Plus. With a shake of her head, the doctor said, “We’ve been seeing that a lot this year. The mild weather means there are more fleas than usual, but the real problem is the topical flea preventatives. Some of them have been around for so long that they really aren’t very effective at all against fleas. I would advise switching to an oral flea and tick preventative from now on.”  She explained that, just like many medicines, flea treatments can lead to strains of fleas that are resistant to the treatments. It’s the kind of evolution we don’t want (rather like antibiotic resistant germs). The vet gave Soldier a chewable flea treatment that she said would last about two weeks and asked me to bring Soldier back in for a follow-up in 7-10 days. Although he hasn’t yet been back to the vet’s office, I can vouch for the fact the Soldier is still “flea free.”

What has your experience been with the topical flea preventatives? Have they worked well for you in the past? Have they lost their effectiveness? What about side effects? There are lots of questions I’ve been asking since this new development. Since the topical flea preventatives worked well for years, I came to rely on them. After doing some research, I’m hesitant to ever go back to a topical treatment and am researching the alternatives. I’d like to learn more about alternative, non-chemical treatments as well. What do you use? Why? I’d love your input!