There are several products which work against fleas but in all of them the
active ingredient is an insecticide.Unfortunately there is no product which
works against fleas and does not have an insecticide as an active ingredient.
There are several products on the market with active ingredient other than
Imidacloprid and Permethrin, which is contained in K9Advantix and K9Advantix II.
There is Frontline Plus with active ingredient (fipronil and S methoprene),
Capstar with active ingredient Nitenpyram which is very well tolerated by pets.
Fleas are insects and to kill them, you need to use a product which has an
insecticide as an active ingredient. My advice is to use Frontline Plus or
Capstar because the side effects are low.