Flea & tick prevention for cats weighing over 1.5 pounds. This fast-acting, quality flea and tick control for cats starts killing fleas, ticks, and chewing lice within 24 to 48 hours. This waterproof topical flea and tick treatment kills and prevents fleas, flea eggs, flea larvae, ticks, and chewing lice for up to 30 days. 3-month supply.