Frontline Spot on Cat is for the prevention Fleas and Ticks in cats, and is part of a treatment strategy for Flea Allergy Dermatitis in cats where this has been previously diagnosed by a Veterinary Surgeon. Frontline Spot On Cat controls infestations with biting lice on cats. It is effective against fleas for up to 5 weeks and ticks for up to 1month in cats. It also controls lice within 48 hours. Routine treatment is advised to prevent flea infestations.