Yes, this flea spray is toxic to cats because it contains an insecticide called pyrethrin. However, all insecticides are toxic to cats. I think this one is particularly troublesome because it is a spray which you spray onto the code of a cat. The cat licks it off and ingests the chemical. This poisons the cat. The cat firms at the mouth and causes great concern to the cat’s owner. This is manufactured in Australia and sold in Australia. I don’t think this product is sold elsewhere by the way. This is an Australian story essentially.