Quote Originally Posted by AdoreMyDogs
I have used many different types of flea shampoos. They all have killed the fleas instantly. They then become re infested within an hour or two. The shampoos I have bought and used were not only supposed to kill fleas, but their eggs and larvae as well. They all advertise being effective on the animal for up to 14 days. They're not even effective on the animals 3 hours

Hence the reason I have this part included in my 'standard flea speech' I use at work.

Quote Originally Posted by Catlady711
Most OTC flea products only kill the existing adult fleas on your pet at that moment. So you can bathe away in a chemical laden bath and the moment you set your pet back on the floor...whamo, you've got fleas again. Also since the pyretherins have been used for so many years many fleas have become immune to the effects of them resulting in poor perfomance of the product.