Frontline Plus Flea & Tick Spot Treatment for Cats, over 1.5 lbs, 3 Doses (3-mos. supply); Help protect your kitty from pests with Frontline Plus Flea & Tick Spot Treatment for Cats, over 1.5 lbs. This treatment kills adult fleas, flea eggs, flea larvae, chewing lice, and ticks. It’s formulated with two active ingredients—fipronil and (S)-methoprene—to help disrupt the flea life cycle and inhibit future infestations. Plus, it’s designed to be waterproof after 24 hours, fast-acting, and long-lasting—one easy topical application works for 30 days. This treatment is paw-fect for cats weighing over 1.5 pounds.