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All the Latest Deals, News and More: > Flea & Tick Control > Spot On > Item # 405589

K9 Advantix II for Dogs 6-Month Supply

Regularly: $87.99
Today's savings: 25%

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In Stock. Usually Ships within 24 hours.



In Stock. Usually Ships within 24 hours.



In Stock. Usually Ships within 24 hours.

Over 55lb


In Stock. Usually Ships within 24 hours.

Shipping weight = 0.10 lb.


Product Summary:

K9 Advantix II Dog: 6-Month Supply

K9 Advantix II delivers pest protection through topical action. It protects against fleas (flea eggs and larvae), ticks, mosquitoes, biting flies, and lice. It combines imidacloprid and permethrin with insect growth regulator pyriproxyfen, which interferes with the hormone signaling of molting insects so that fleas in immature stages are unable to molt. K9 Advantix II is for monthly use on puppie as young as 7 weeks old and dogs. Do not use on cats.

  • Repels and kills ticks, fleas, and mosquitoes
  • Repels biting flies
  • Kills lice
  • Kills all life stages of fleas
  • Prevents development of fleas, flea eggs, and larvae
  • Kills fleas within 12 hours of initial application
  • Kills reinfesting fleas within 2 hours
  • Protects against ticks that may transmit organisms that can cause Lyme disease, Rocky Mountain spotted fever, Ehrlichiosis, and Anaplasmosis
  • Waterproof: continues to work after a bath or weekly swimming (for optimal results, use a non-detergent shampoo)
  • One application lasts for a month
  • Can be used on puppies as young as 7 weeks old
  • Easy-to-follow application instructions on the back of every package
Item Specifications:

4-10 lb.: Green
11-20 lb.: Teal
21-55 lb.: Red
Over 55 lb.: Blue

Includes six applicators

Apply the entire contents of the tube evenly to two to three spots on the top of the back from the shoulder to the base of the tail. Monthly application.

Length of Effectiveness:
Under normal conditions, the product is effective for a month. However, in cases of severe flea infestation, retreatment may be necessary earlier than four weeks. Do not retreat more often than once every seven (7) days. After flea control is attained, return to a monthly retreatment schedule.

8.80% Imidacloprid
44.00% Permethrin
0.44% Pyriproxyfen
46.76% other ingredients
Active ingredients work synergistically. The combination of imidacloprid with permethrin exerts a unique synergistic effect on the arthropod nervous system that is greater than either ingredient alone. Each compound acts on a different receptor area of the nerve cell:

  • Imidacloprid: (nicotinic receptors) irreversibly opens nicotinic receptors on postsynaptic neurons, resulting in constant neuromuscular stimulation, spastic paralysis, and death
  • Permethrin: (sodium channels) causes prolonged sodium ion exchange across neuronal membranes, resulting in constant nerve discharge followed by spastic paralysis and death
  • When both ingredients are combined, the neurotoxic stimulation is greater than that seen with either ingredient alone
Downloadable Resources
Comparison ChartK9 Advantix II vs Frontline Plus
MSDSK9 Advantix II
Style Item Number Model Number UPC
4-10lb 405589 001 5420364 724089203649
11-20lb 405589 002 5420380 724089203809
21-55lb 405589 003 5420402 724089204028
Over 55lb 405589 004 5420429 724089204295

Product Reviews by Customers

4.7 / 5.0
23 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Pet Satisfaction
Disappointed (2)
Happy (2)
Pet Satisfaction
K9 Advantix?
I would love to write a review of K9 Advantix, but in order to do that, would have to actually send it to me instead of the Seresta collar they sent (which doesn't work very well).
July 23, 2018
3 months ago
Age of Pet (years):
What is your pet?:
Dog - Large
Pet Satisfaction
Excellent results an price not to bad
Works an will continue to use it..other products caused skin problems
July 21, 2018
3 months ago
Age of Pet (years):
What is your pet?:
Dog - Large
Pet Satisfaction
good product
Product is as advertised and shipped quickly
May 23, 2018
5 months ago
Age of Pet (years):
What is your pet?:
Dog - Large
Pet Satisfaction
better than most
I've had lyme disease with one of my hounds while using another product. No issues since changing. One of my breeders recommended I switch
April 5, 2018
1 year ago
Age of Pet (years):
What is your pet?:
Dog - Large
works for my 3 huskys
September 21, 2017
1 year ago
Age of Pet (years):
What is your pet?:
Dog - Medium
Awesome service was wonderful, I accidentally ordered the wrong weight for thus product and it was a hassle free exchange. Thanks so much for a great online experience.
June 6, 2017
This product works well for my dog.
I have used this product for a few years now and it works very well to repel ticks and fleas in our area. My Pooch likes to spend a lot of time in the woods and trees and can get covered in a short amount of time.
May 1, 2017
I have been using this after one of my dogs got Lyme disease while on Frontline Plus. I have been using this for 5 years now and I have yet to be disa
There is no the product 4 small breed dogs then Advantix the price the value and the worry-free makes it priceless to us we have dogs that weigh from 25 pounds and dogs that weigh 3 pounds and 5 pounds.
August 22, 2016
Great product
I have used this for many years!!! Works Great!!!!
August 8, 2016
K9 Advantix 2
When frontline stopped working on my girls i tried several other products that ended up not working. I saw an advertisement for this and decided to try it. So far I love it. I also like that it treats not only fleas and ticks but also mosquitoes. All 3 are a big problem where we live.
June 22, 2016
Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 9 questions Browse 9 questions and 70 answers
Why did you choose this? Store
I have used this product for years and I know it works!
Melissa K on Sep 21, 2018
This is the best flea medication that I have found ! It works great at ridding fleas, and it's reasonably priced !
CHARLENE A on Aug 9, 2018
I have used this product for years and I know it works!
Melissa K on Sep 21, 2018
I have never used any other flea/tick medication but K9 Advantix II and I have NEVER had any problem with fleas or ticks! And I am talking about living in the hot, humid environments of South Texas and South Florida where it is flea and tick season all year long!
Janice B on Aug 31, 2018
This is the best flea medication that I have found ! It works great at ridding fleas, and it's reasonably priced !
CHARLENE A on Aug 9, 2018
it works
VIRGINIA L on Jul 11, 2018
Requirement for my area to keep fleas under control.
Sara J on May 25, 2018
good service, easy website, great sale price, free shipping
raymond b on May 25, 2018
Summertime flea meds are important for my 4 dogs.
JOAN D on May 20, 2018
It works!
Kirk M on May 2, 2018
Great product!
Laurie J on Mar 28, 2018
I need to get flea/tick/mosquito preventative medicine for my dog.
Wendy H on Mar 8, 2018
I use this product because I do not ever have trouble with fleas when I do. We live in the hot and humid southern part of Texas, so fleas can be a constant bother, even in the winter. I keep this on my dogs year-round and apply it every 4 to 5 weeks. It works like a charm. It is a little pricey, but so is fumigating your house to get rid of fleas!
Janice B on Feb 8, 2018
it works well
dan k on Dec 26, 2017
needed it
Brian W on Sep 26, 2017
This product works.
Bruce W on Jul 26, 2017
we live in the country and this is the only flea medicine that actually seems to work.
joanna r on Jul 15, 2017
VICKI 041618 B on Jun 28, 2017
Great price! I have a foster dog that just tested positive for heartworm, so will be staying with me longer than I anticipated and I need to cover him for flea/ticks for the 8+ weeks he will be here. This is a lot less expensive than over-the-counter at the vet office. Thanks!
CHRISTINE R on May 15, 2017
Need to protect my dog and the reviews were very good on this brand
JETTA C on May 8, 2017
This one works best for sandfleas
Julie L on May 5, 2017
We are campers and always in the woods. My dogs never have trouble with fleas and ticks using this product.
Chris C on Apr 14, 2017
Chose this item because it actually works!
Debra M on Apr 13, 2017
Ive used this product and it works
Charles K on Mar 31, 2017
works better than any spot on that I've tried
Rick the plumber on Mar 31, 2017
LEE H on Mar 15, 2017
Proven to work.
Laurie J on Feb 20, 2017
only thing that seems to work
NINA G on Feb 10, 2017
We have used K9 Advantage for many years and have always been satisfied with how it keeps our dogs flea free.
Donald P on Jan 2, 2017
vet recommended
Howard E on Nov 14, 2016
I chose Advantix II because it protects my dog from ticks too. I've been using advantage II. I thought it would protect my dog from ticks too, but it didn't. My dog has one tick disease, Annapasma (?) now. He doesn't show any symptoms. This is why I'm purchasing Advantix II. I don't want any other problems.
Barbara S on Oct 5, 2016
flea and tick time.
TERESA E on Oct 5, 2016
Been using it and have been happy with it, needed more
LYNETTE L on Sep 20, 2016
I've used it before and it seems to work well. The price was a lot better for the same product than that in the Dr Foster and Smith catalog, since I had a 30% discount.
GAIL G on Sep 7, 2016
Have reverted to using Advantix II after using other failed products in a high tick zone.
DEBRA H on Sep 5, 2016
I'm starting to have problems with the advantage not working on my dogs so I thought I'd try advantix instead.
Chris I on Aug 30, 2016
works well with no side effects on my dogs
Direct C on Jul 26, 2016
Price and used it before
James W on Jul 23, 2016
It not only kills & repels ticks & fleas but it also does the same to mosquitoes which a lot of brands do not
Michele E on Jul 23, 2016
we don't want fleas
Becky P on Jul 22, 2016
recommended by vet. Seems very effective.
Leslie A on Jul 20, 2016
Great price and fast ship!
Kelly D on Jul 8, 2016
Effective product and great price.
Linda B on Jul 4, 2016
Great value for a quality product
Jazzerine A on Jun 12, 2016
I purchased for my four German Shepherds, it keeps them free of all pests
Carmella L on Jun 6, 2016
Best working flea and tick treatment I have used.
Gary J on May 24, 2016
It seems to work better than other products plus price is great deal.
Robert B on May 23, 2016
Good product easy to use.
SCOTT M on May 16, 2016
This product works the best out of all the others I've tried (and I've pretty much tried them all!) plus there aren't any side effects on my pets.
Highly recommend!
PATTY R on May 4, 2016
K9-Advantix is THE BEST and has saved my dogs life more than once. I have 5 dogs now and use NOTHING but the K9- Advantix for them and it is SOOOO IMPORTANT that they are covered. We live in the deep south (southern Arkansas) and the mosquitoes are as common as the hills and they MUST be protected! So for peace of mind, we use NOTHING best. Why mess with success!
Gail C on May 2, 2016
it works
WILLIAM R on May 2, 2016
I know it works
Christopher D on Apr 13, 2016
I have never used any other flea/tick medication but K9 Advantix II and I have NEVER had any problem with fleas or ticks! And I am talking about living in the hot, humid environments of South Texas and South Florida where it is flea and tick season all year long!
Janice B on Aug 31, 2018
it works
VIRGINIA L on Jul 11, 2018
how soon after application can i bath my pet?
A shopper on Jul 9, 2014
BEST ANSWER: My dog groomer tells me it's okay by the next day because it goes into the pores of the skin.
Hi I am wondering if we receive 25% off everything in our cart including sale items?
First Name L on Jun 30, 2014
I have English Mastiff that weighs 225. lbs what size would i need for him??
Stephen S on Oct 30, 2015
BEST ANSWER: Over 55lbs: Blue
Number of applications per package?
A shopper on May 4, 2014
BEST ANSWER: In the 6 month supply package, there is one application per month for a total of 6 months of protection.
Does it smell?
Freddy Boy on Apr 19, 2017
BEST ANSWER: I have used the product for years. It is excellent at keeping my dogs tick free and we have never had a case of fleas. There is no odor when using it.
How long do I have to wait after letting my dog outside until after I put K9 Advantix II if it is raining?
Pet Parent on Mar 19, 2018
BEST ANSWER: This item is waterproof and states to wait 24 hrs after applying before getting wet. If pet is in a light rain then should be fine, but if its pouring out waiting the 24hrs after applied would be the best way to not have item wash off.
I have a WestHighland Terrier who weighs about 10-11 lbs. Which should I buy the 4-10 or 11-20lb?
Jeanette S on Apr 30, 2017
BEST ANSWER: It would be best to consult with your vet as to the best size to purchase. Too little will be ineffective and too much may make the dog ill.
why is the k-9 advantix so much more now than we purchased it a few months ago?
A shopper on Aug 14, 2017
BEST ANSWER: Maybe you haven't taken advantage of email offers of discounts and specials. If not, sign up and save!