Say bye-bye to pesky pests with K9 Advantix II Medium Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention. It’s a su-paw simple way to treat and prevent fleas, ticks, mosquitoes, biting flies and lice. This treatment repels pests and kills fleas on contact, so they don’t have to bite your furbaby to die. It starts working within hours of applications. This monthly topical formula is fragrance-free and easy to apply, and there’s no treatment needed. It’s waterproof after 24 hours in case your best friend gets caught in the rain.