Shop / Elanco Deals / K9 Advantix II Large Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | Dogs 21 - 55 lbs. K9 Advantix II K9 Advantix II Large Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | Dogs 21 - 55 lbs. $34.99 21 55 lbs 2 Month 21 55 lbs 4 Month 21 55 lbs 6 Month 21-55 lbs - 2 Month 21-55 lbs - 4 Month 21-55 lbs - 6 Month Purchase Options Free In-Store Pick Up Not Available Set your store for inventory and store pickup details Zip Code Search Same-day Delivery* No minimum charge for delivery orders. *Order before 2pm and have it delivered today. Orders placed after 2pm will be delivered the next day. Must be inside delivery radius. Zip Code Unfortunately delivery is not available to this address. In order to ensure the best availability accuracy, changing your selected store will remove all items from your cart. You will need to re-add these items with your newly selected store if you choose to continue. Continue Cancel Ship it to Me Not Available Quantity Add To Cart Information K9 Advantix II helps defend your dog against fleas, ticks, mosquitoes, biting flies, and lice. Simpler than a flea collar and troublesome pills, this vet-recommended topical formula works within 12 hours of initial application, killing adult fleas on contact to stop existing flea infestations and prevent new ones. Once K9 Advantix II is applied, your dog is ready to get right back to the things it loves most. K9 Advantix II pest protection is effective on both indoor and outdoor dogs. Your dog should be at least 7 weeks old and weigh 21-55 lbs. to use K9 Advantix II Large Dog. K9 Advantix II Large Dog is a trademark of Elanco or its affiliates. Key Features K9 Advantix II Large Dog 30-day treatment & prevention protects dogs 21-55 lbs. from fleas, ticks, mosquitoes, biting flies and lice Kills fleas within 12 hours of application Vet-recommended formula kills & repels on contact so fleas don’t have to bite your dog to die Easy-to-apply topical treatment is fragrance-free and waterproof after 24 hours No prescription needed Customers also liked Customer Reviews