Joni asked 8 years ago
We have 3 cats who have all been treated twice with Frontline Plus. We have one cat that I get no live fleas off of but flea pupae keep falling of her where ever she lays. Another cat has no more fleas and the third I only get one or two slow fleas a day on her. What else can we do about the cat who keeps dropping pupae.
Adam Retzer Staff answered 8 years ago
Hello Joni,
Flea pupae develop in the environment. It’s the eggs that are laid on the host, and then fall off.
The Frontline Plus contains an insect growth regulator, methoprene. This active ingredient will sterilize exposed adult females, so the eggs they lay aren’t viable. Also, exposed eggs won’t be able to develop.
The fleas you’re seeing on your cats are those emerging from the environment. This is where immature fleas develop, and they account for 95-99% of the infestation. When they mature, adults emerge from their cocoons in the carpets. They then jump onto a nearby host. Frontline Plus can take a few hours to kill the new fleas.
The Frontline Plus is sufficient in treating the cats. Keep up the treatments for the recommended duration on the package. Usually this is around 3 months.
To speed up the eradication process, it’s important to vacuum regularly. Vacuuming will remove some of the young fleas, at all stages. It also causes heat and pressure, which are the two cues which trigger adults to emerge from their cocoons. If they don’t detect these host cues, the pre-emerged adults can stay quiescent for up to 5 months.
The pre-emerged adults are what make control difficult. The flea life cycle, from egg to adult, completes in 17-26 days. However, after treatment, it usually takes around 8 weeks (sometimes longer) to completely end an infestation.
It is also helpful to spray the environment with an insect growth regulator (IGR). Precor 2000 Plus, for example. The IGR, methoprene or pyriproxyfen, mimics insect hormones that regulate development. Exposed eggs and larvae in the environment won’t be able to reach adulthood. And the IGR stays active for 7 months indoors, which is useful for preventing re-infestation.
Warm regards,
Adam
