This time of the year it's a daily occurrence to talk to my clients about flea control. Here in the southeast US we have a lot of fleas, especially during the warm weather, so flea prevention is a necessity. Without using it, you're just asking for flea problems. However, many clients apply one dose, a week later see fleas, and complain that it isn't working. Last year I wrote an entry about flea control, which I wanted to remind everyone about (right here). But here's a quick review...
*A single dose of flea prevention will NOT get rid of your flea problem.
*Fleas have to jump on the pet in order to be affected by the topical preventions.
*You have to treat the house and yard in order to completely control the problem.
*Every pet in the house must be treated.
*You can't bathe your pet too often or you will cause the product to work less effectively.
*Once you start seeing fleas it will take you several months to get the problem under control.
*Flea medications work best as prevention, before you see fleas.
So basically you need to use the topical products from your vet very consistently every single month, treat the environment, and avoid overbathing. All of the current veterinary products (Frontline, Advantage, K9 Advantix, Vectra, etc.) are indeed effective, but must be used regularly and appropriately in order to work. Don't give up after a single dose!