K9 Advantix II Medium Dog Flea, Tick & Mosquito Treatment — 11–20 lb, 6-Month Spot-On Protection

K9 Advantix II Medium Dog is a once-a-month topical treatment that kills and repels fleas, ticks, mosquitoes, biting flies and lice for dogs weighing 11–20 pounds.

This veterinarian-recommended spot-on formula delivers fast, broad-spectrum pest defense in a simple application. Designed for dogs at least 7 weeks old, the liquid pipette goes on in seconds, becomes waterproof after 24 hours, and starts eliminating adult fleas quickly so they can’t reproduce. Available without a prescription in multi-dose packs, K9 Advantix II is made to fit busy pet routines while protecting indoor and outdoor dogs from common vectors of irritation and potential disease.

How quickly does this treatment stop fleas and prevent new infestations?

After a single application, this topical begins killing adult fleas fast and prevents new eggs from being laid by treating pests on contact. That rapid action helps break the flea life cycle and reduces the chance of reinfestation when used monthly.

• Kills adult fleas within 12 hours of initial application
• Works on contact so fleas don’t need to bite to die
• Monthly use prevents flea eggs and future generations
• Suitable for both indoor and outdoor dogs

Will it protect my dog from ticks, mosquitoes and biting flies too?

Yes — the formula is multi-targeted and both repels and kills ticks, mosquitoes and biting flies in addition to fleas. That broader protection helps reduce nuisance biting and lowers exposure to pests that can transmit pathogens.

• Active against several species of ticks common on dogs
• Repels and kills mosquitoes that can irritate pets
• Reduces bites from stable and other biting flies
• Part of a regular prevention routine for outdoor dogs

How do I apply K9 Advantix II and is it safe for everyday life with my dog?

The product is applied topically between the shoulder blades in a few drops; it spreads across the skin and coat. It’s fragrance-free, becomes waterproof after 24 hours, and allows dogs to resume normal activity shortly after treatment.

• Simple spot-on pipette application — goes on in seconds
• No pills to swallow or collars to adjust
• Waterproof after 24 hours; avoid bathing right after application
• Check label for detailed directions and possible side effects

How often should I use it and what sizes are available?

Use once every 30 days to maintain continuous pest control. K9 Advantix II comes in multi-dose packs so you can stock up and avoid missed treatments.

• Monthly administration for ongoing protection
• Available in 2-dose, 4-dose and 6-dose pack sizes
• Designed specifically for dogs weighing 11–20 lbs (Medium)
• OTC availability — no prescription required

Who this is for: K9 Advantix II Medium Dog is geared toward pet owners who want fast-acting, monthly topical protection for small-to-medium dogs (11–20 lbs) that spend time indoors and outdoors. It’s a good fit for households that prefer a fragrance-free, waterproof solution without prescriptions or oral medication, and for anyone aiming to interrupt the flea life cycle while also managing ticks, mosquitoes, biting flies and lice. Always read the product label for age, weight requirements and safety guidance before use.

Ingredients

Imidacloprid 8.80% Permethrin* 44.00% Pyriproxyfen 0.44% Other Ingredients 46.76%