You can use the same flea products on dogs and cats, right? Wrong!! Unfortunately, what may be safe for use on your pooch may be highly toxic to kitty!! One such example is pyrethrin and its’ derivatives, which are used in some flea and tick control products. Natural pyrethrins are derived from the Chrysantemum plant- yes, that very innocent looking flower! The products containing pyrethrin are usually in ‘top-spot’, rinse or spray form.