I had somewhat of a flea problem in my house within the last week. After I caught it I applied medication (Frontline and Paradyne) to the dog and cats, kept them separate, spread diatomaceous earth, and vacuumed like crazy.

I'm fairly certain my dog she cats are flea free but the dog is still chewing and scratching. I can't tell if he's just scratching old bites or still has them. I can't find any fleas or dirt on him.

How can I be sure he's flea free?

  • Hard to prove a negative but you could set a flea trap near where the dog sleeps and inspect it.
    – paparazzo
    Commented Nov 4, 2015 at 12:30

2 Answers 2


If you only used diatomaceous earth (DE) last week you can be certain that you still have fleas in your home and on your pets.

As you also used Frontline and Paradyne on the dog and cats, you can be relatively sure fleas will not survive on them. In this case you are breaking the fleas life cycle, female fleas need to have a blood meal in order to breed. If they try to get that meal from one of your treated pets, they will die and the life cycle will be broken. You may want to continue this treatment for few months, if not indefinitely.

DE is only effective on adult fleas at any given time only about 5% of the fleas in your home are adults. There some health concerns with DE, so repeated applications and removal is the recommend path to control fleas.

To effectively control fleas with DE requires multiple applications, treatments and cleaning. There is a detailed write up about at Die Fleas! Die! Die! Die! Freaky Cheap Flea Control

Fleas can feed from the humans in the house, keeping yourself, clothing and bedding clean should control their ability to complete a life cycle using human blood.

Flea control, does not mean total extermination. There will always be some risk of fleas re-establishing themselves in your home.

You indicate you dog is still scratching, we have an answer indicating pets can have allergic reactions lasting weeks or months after the fleas are gone., if this is the case you may want visit a vet for diagnosis and treatment. Related Question What could cause my dog to bite/pull her own hair out?

  • My approach, the one time we had a flea problem: Discard the cat bed. Launder human bedding. Bomb the house twice, at the recommended seperation, with an aerosol that specifically targets insect eggs, to break the cycle. Flea-shampoo, dry, flea-comb the cat, repeating until I was no longer finding fleas. Then put a flea collar on her (this was long before frontline et al) and trust that she would effectively sweep up any bugs which survived all of that. Seemed to work. Luckily she was a very patient lady and was willing to be bathed. Handheld lowpressure spray, warm, long drying cuddles.
    – keshlam
    Commented Nov 7, 2015 at 2:40

Have you tried looking at your dog? He/she may be flea free but could have hot spots still which are itchy and painful. As to your house it really depends on what else you've done. DE isn't going to completely eradicate the fleas. I suggest you bomb the entire house. Maybe twice.
Now, Now, not rudeness intended here but your animals had to have had quite an infestation of fleas for a while to infest your house so badly. If your animals are regularly treated this should not be an ongoing concern. A bath now and then helps. I'm from the country where my dogs were exposed daily to fleas, ticks, mites etc. and I never had trouble in the house or my truck. Frontline is a good product. Brewers Hyatt in their food also is a great help.
Good luck

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