Frontline Spray in a handy spray pack is a fast acting, long lasting insecticidal spray for the control and prevention of parasites on dogs and cats. It is a topical liquid (applied in a spray f orm) for the treatment and prevention of flea infestation, and control of adult brown dog tick and paralysis tick. Frontline spray starts working almost immediately, and prevents re-infestations of new adult fleas for up to 12 weeks on dogs and 8 weeks on cats, and ticks for up to 3 weeks on dogs and cats. Use only as directed on the label.