Skip to product information
1 of 9

K9 Advantix II for Medium Dogs 11-20 lbs Flea Tick Mosquito Treatment 6 Doses

K9 Advantix II for Medium Dogs 11-20 lbs Flea Tick Mosquito Treatment 6 Doses

Regular price $55.40
Regular price Sale price $55.40
Sold out
29 people are viewing this right now

Shipping & Returns

Free USA Shipping on Orders Over $120

We ship all US domestic orders within 1-3 business days

Returns & Refunds Policy

30-Day Return Policy

We offer a 30-day return policy from the date of delivery.

To qualify for a return:


  • The item must be unused

  • The item must be in original packaging

  • Proof of purchase is required

Non-Returnable Items

The following items cannot be returned:


  • Opened pet food or treats

  • Personalized products

  • Clearance or final sale items

  • Hygiene-related pet products

Damaged or Incorrect Items

If you receive a damaged or incorrect product:


  1. Contact us within 72 hours of delivery

  2. Provide photos of the product and packaging

  3. We will arrange a replacement or full refund

Return Shipping


  • If the return is due to our error (damaged or incorrect item), we cover return shipping

  • If the return is due to customer preference, the customer pays return shipping

Refund Processing

Once we receive and inspect the returned item:


  • Refunds will be issued to the original payment method

  • Processing time: 5–10 business days
View full product details

Keeping your dog safe from fleas and ticks is important, especially if they love spending time outdoors. K9 Advantix II for Medium Dogs is made for dogs weighing between 11 and 20 lbs and offers reliable monthly protection against fleas, ticks, mosquitoes, biting flies, and lice.

This easy-to-use topical treatment starts working quickly and helps kill fleas within 12 hours of application. It also repels pests before they bite, helping your dog stay comfortable and protected throughout the month. The formula works by targeting adult fleas, flea eggs, and larvae to help reduce reinfestation in your home.

Each pack includes 6 doses, giving your dog up to 6 months of continuous protection. The waterproof formula remains effective after bathing or swimming once fully dried, making it a great option for active dogs.K9 Advantix II is simple to apply and does not require a prescription. Just apply one tube every 30 days to help protect your dog from common parasites that can cause itching, irritation, and discomfort.

Product Benefits

  • Suitable for medium dogs weighing 11-20 lbs
  • Helps kill fleas within 12 hours
  • Repels ticks, mosquitoes, biting flies, and lice
  • Waterproof formula after 24 hours
  • Easy monthly application
  • 6-dose pack for long-lasting protection
  • Helps control flea eggs and larvae
  • Suitable for dogs and puppies over 7 weeks old

How to Use

Apply the contents of one tube directly to your dog’s skin between the shoulder blades once every month. Make sure your dog’s coat is dry before application for the best results.

Why Pet Owners Choose K9 Advantix II

Many dog owners trust K9 Advantix II because it offers broad protection in one simple treatment. Whether your dog enjoys walks in the park, outdoor playtime, or daily adventures, this treatment helps keep pests away and supports your dog’s comfort and wellbeing.

FAQs

1-How long does K9 Advantix II last?

Each dose provides protection for up to 30 days.

2-Can I use this product on puppies?

Yes, it is suitable for puppies over 7 weeks old weighing between 11 and 20 lbs.

3-Is the formula waterproof?

Yes, once dried after 24 hours, the treatment remains effective even after bathing or swimming.

4-What parasites does it protect against?

It helps protect against fleas, ticks, mosquitoes, biting flies, and lice.

5-How many treatments are included?

This pack contains 6 monthly doses.

  • 5 stars: 18 (78%)
  • 4 stars: 5 (22%)
  • 3 stars: 0 (0%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
H
Henry Wallace

My 13-pound dog has been using this for a few months, and I’ve had a good experience. The monthly applicators are easy to use, and I appreciate not having to buy treatments separately every month.

N
Natalie Cooper

I’m happy with this flea and tick treatment. It’s simple to apply, doesn’t create a mess, and my dog handled it without any problems. Delivery was fast, and the product arrived sealed properly.

M
Marcus Bennett

This has worked well for my medium-sized dog. I spend a lot of time outdoors with him, and this treatment helps me feel more prepared. The six-month supply is a great value and easy to manage.

O
Olivia Harper

I’ve been using this treatment on my 15-pound dog, and it has been very convenient. The application is quick and easy, and I like having six doses ready to go. My dog stays comfortable, and the package arrived safely.

G
Grace

After several months of use, I've found this treatment convenient and straightforward. The six dose box is economical for long term use and the monthly schedule is easy to remember.

N
Nicholas

The product has generally met my expectations. It was easy to apply and my dog didn't seem uncomfortable afterward. I would have liked slightly more detailed application illustrations, but the written directions were still clear enough.

R
Reed

I like the overall design of the packaging and how each dose is separated. The product has been easy to handle and doesn't require much effort to apply.

B
Brandon

This treatment has been reliable for my dog, who weighs around 18 pounds. The applicator is simple and the packaging keeps everything organized.

C
Cooper

I appreciate the convenience of having flea, tick and mosquito protection together. The instructions were easy to understand even for someone using this type of treatment for the first time.

S
Sanders

I've been satisfied overall. The product offers good value because each box contains six treatments. My only suggestion would be to include a small reminder calendar inside the package, but otherwise it's easy to use and practical.

M
Mitchell

This has been a dependable product for our family pet. The formula is simple to apply and I like that one purchase covers multiple months.

P
Parker

My dog enjoys spending time in the yard so I wanted something that covered more than just fleas. I appreciate the added mosquito protection.

E
Emily

I have mixed feelings. The product was easy to apply and arrived well packaged, but I would have preferred a slightly easier to open applicator.

R
Richardson

The application process was cleaner than I expected. I appreciate that each tube is clearly labeled, making it difficult to confuse the dosage.

N
Natalie

I bought this before the summer season and found it helpful for our camping trips. The instructions were clear and applying the treatment only took a minute.

A
Andrew

The product seems well made and easy to use. I like that it combines protection against multiple pests instead of requiring separate treatments.

S
Sophia

After trying several options, I found this one straightforward to apply. My dog didn't seem bothered after treatment and I noticed fewer pests around her coat.

O
Olivia

This product has become part of my dog's monthly routine. I appreciate the clear dosage for medium dogs, which makes it easy to choose the correct version.

B
Brian

I've had a mostly positive experience with this treatment. It helped control fleas effectively, although I wish the liquid dried a little faster.

S
Simmons

Overall, this has been a good product. It appears to reduce flea activity significantly, although I still check my dog after hiking trips.

N
Nolan

I like how simple the monthly application is. My dog spends a lot of time outdoors, so having flea, tick and mosquito protection in one product is convenient. I

M
Melissa

This treatment has worked well for my medium sized dog over the last few months. I noticed fewer fleas within a day and my dog seemed comfortable after application.

D
Daniel Harper

I've been using K9 Advantix II for my 15 lb terrier and it has done a solid job keeping fleas and ticks away. The applicator is easy to use and the treatment dries fairly quickly.