I took my cat in for itchy skin, and the vet is convinced that he has fleas. I'm less convinced. She found flea dirt on him, which she verified because it turned rusty looking when she put it on a piece of gauze and wet it. BUT, I live in the middle of NC and our DIRT is partially red clay. Also, he gets itchy about once every year or so, and it's NEVER been fleas. Anyhow, she switched us to Revolution, since that will also prevent heart worms (and he does go outside in our fenced patio sometimes).
I still am not convinced my cat had fleas (since I've never seen ANY on him OR the dog or anywhere else in the house), but I thought I'd share that info about the vet thinking Frontline isn't working as well these days.
We resorted to advantix 2 weeks ago and that didn't work. Today we tried to Comfortis and the fleas are dying and falling off him. YUCK! Many more than we thought. I was so sad about it, but we tried so many things (incl'ing baths every other day which was terrible for his skin). We figure we'll do this to help him and then use natural methods to maintain. I read that baking soda mixed with eucalytus essential oil is a good preventative, or even rose geranium EO on collar.
We raked our leaves in the yard, as another thread poster said that seemed to help their dog.
You have to understand the flea life cycle to understand why. 95% of ALL The flea population in your home are EGGS. Every day that you have fleas, those adult fleas are adding to those eggs. You must continually kill all the adult fleas EVERY DAY in order to stop the reproduction, and THEN you have to let the eggs hatch into pupa (because you won't get ALL of the eggs not even with sprays and vaccuming), and then the pupa into baby immature fleas (these can't reproduce). Now, if you have a topical flea product on at this time, the immature fleas will bite the animal and will die before they can reproduce more eggs. If you aren't killing these fleas daily, the cycle will go on and on and on and on.
I recommended Advantix or Advantage. The vet I work for is having us stray away form Frontline, because soon it will be available in all retail stores, instead of just vet offices. Stay away from Bio Spot and all the other crummy products you find on the shelves of normal stores. They contain just a wee bit of the chemical that kills fleas, and the fleas can actually build up a resistance.
You'll need to do a LOT of vaccuming, a lot of laundry, a lot of bathing/flea dips (every day) if you want to get rid of fleas without chemicals. Growing up we had fleas with the dogs and we didn't use chemicals. The BEST we could ever do was to keep fleas to a minimum, but we NEVER got rid of them entirely until all the animals were on a topical flea preventative.
Frontline and Advantage WILL work, but it will take a few months. Truly, ANY method of flea control will take months to work.
We use the Advantix on our dog, and she has certainly never gotten any fleas.
But, then again, I'm still not convinced my cat actually had fleas. He sleeps against my face at night, and you'd think I'd know!
I haven't seen a single flea since switching my dogs to a prey model raw diet. When dogs and cats are fed raw, their blood tastes different to fleas and they don't like it. You can also use food grade DE in the house and yard and neem in their shampoo, but we haven't needed to use any of it since switching to raw 2 years ago.
Edit: I live in Florida where the fleas are typically really bad year round.