• 6 MONTH K9 Advantix II RED for Large Dogs (21-55 lbs)

6 MONTH K9 Advantix II RED for Large Dogs (21-55 lbs)

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Regular Price: $101.99Sale Price: $74.95
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K9 Advantix II RED for Large Dogs 21-55 lbs

Keep your dog safe from irritating and dangerous pests with k9 Advantix for dogs 21-55 Lbs. Formulated for dogs seven weeks of age and older and weighing 21-55 pounds and under, K9 Advantix II outperforms its competitors not only by killing more varieties of pests, but also by repelling them to prevent future attacks.

Repels and Kills Ticks, Fleas, and Mosquitos

The active ingredients in K9 Advantix II help keep your dog safe from ticks, fleas, and mosquitoes. These effective compounds attack the pests' nerve cells, paralyzing and effectively killing them, as well as repelling them from future attacks. Most ticks are repelled and killed before they can attach, which may reduce the risk of transmitting disease-causing organisms to your pet. K9 Advantix II effectively kills and repels Deer ticks, American dog ticks, Brown dog ticks, and Lone Star ticks.

K9 Advantix II for Large Dogs up to 21-55 lbs
  • Kills and repels ticks, fleas, and mosquitoes
  • Repels biting flies and kills lice
  • Waterproof formula won't wash off from swimming or bathing
  • Includes six convenient one-month doses
  • Easy to apply
  • For dogs seven weeks of age and older and weighing 21-55 pounds and under
  • Per Dose: $11.17
Dog flea life cycle
K9 Advantix II and Frontline Plus Comparison Chart
Fights Against Fleas at All Stages of Development

K9 Advantix II protects your pet against fleas at all stages of the parasite's development. K9 Advantix II breaks the flea life cycle by killing the living fleas on your dog before they can lay eggs. It also prevents the development of existing flea eggs, larvae, and pupae, helping to prevent future infestations.

K9 Advantix II also kills reinfesting fleas (newly hatched fleas jumping back on your dog) within two hours, and it prevents fleas on a treated dog from infesting your home.

Effective Against Biting Flies and Lice

In addition to complete tick, flea, and mosquito protection, K9 Advantix II also repels painful biting flies from feeding on your dog, and it effectively kills up to 100 percent of lice within one week of treatment.

Waterproof Formula

K9 Advantix II is waterproof, so there's no need to reapply after your dog has a bath or goes for a swim. Studies show that dogs are still protected against parasites after exposure to water, though for best results, dogs treated with K9 Advantix II should be bathed with a non-detergent shampoo.

Package Contents

Box includes six 2.5-milliliter tubes of K9 Advantix II for Large Dogs 21-55 pounds.

Flea Cycle

Usage Info

How to Apply

Applying K9 Advantix II to your pet is a fast and easy process. First, remove the K9 Advantix II applicator tube from its packaging and use scissors to peel down the foil. Next, hold the applicator tube in an upright position and pull the cap off the tube. Use the upturned cap to break the protective seal, and you're ready for application.

For easiest application, your dog should be standing upright. Evenly apply the entire contents of the K9 Advantix II tube to two or three spots from the back of the shoulder to the base of the tail. Part the hair at each spot until the skin is visible, then place the tip of the tube on the skin and gently squeeze out a portion of the solution. Be careful not to apply an excessive amount of the solution in any one spot, otherwise some of the solution might run off the side of your dog. Dispose of the container and do not reuse or refill. Do not empty unused product in any indoor or outdoor drain.

For optimal control and prevention of parasites, use K9 Advantix II every month. K9 Advantix II is available in four- and six-month supplies. Do not use K9 Advantix II on cats or any animals other than dogs.

Application Instructions

Evenly apply the entire contents of the tube to four to six spots on the top of the back--from the shoulder to the base of the tail. Apply monthly.

Length of Effectiveness

Under normal conditions, the product is effective for one 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 days. After flea control is attained, return to a monthly retreatment schedule.

Hazards to Humans

Causes eye irritation. Harmful if swallowed. Do not get in eyes or on clothing. Avoid contact with skin. Wash hands thoroughly with soap and warm water after handling.

Hazards to Domestic Animals

*For external use on dogs only.
*Do NOT use on animals other than dogs.
*Do NOT use on puppies under seven weeks of age.

Do not get this product on dog's eyes or mouth. Consult your veterinarian before using this product on debilitated, aged, pregnant, or nursing animals. Individual sensitivities, while rare, may occur after using any pesticide product for pets. If signs persist, or become more severe, consult a veterinarian immediately. If your animal is on medication, consult your veterinarian before using this product.

Do Not Use on Cats

Due to their unique physiology and inability to metabolize certain compounds, cats must not use this product. If applied to a cat, or ingested by a cat that actively grooms a recently treated dog, this product may have serious harmful effects. If this occurs, contact your veterinarian immediately.

Environmental Hazards

This product is extremely toxic to fish. Do not add directly to water. Do not contaminate water when disposing of product or package.

First Aid

Have the product container or label with you when calling a poison control center or doctor, or when going for treatment.

If in eyes: Hold eye open and rinse slowly and gently with water for 15 to 20 minutes. Remove contact lenses, if present, after the first 5 minutes, then continue rinsing eye. Call a poison control center or doctor for treatment advice.

If swallowed: Call poison control center or doctor immediately for treatment advice. Have person sip a class of water if able to swallow. Do not induce vomiting unless told to do so by the poison control center or doctor. Do not give anything by mouth to an unconscious person.

If on skin or clothing: Take off contaminated clothing. Rinse skin immediately with plenty of water for 15 to 20 minutes. Call a poison control center or doctor for treatment advice.

To physician: Treat patient symptomatically.

Keep out of reach of children.



How long does K9 Advantix last?

A single application of K9 Advantix keeps working for one month.

How often should I use K9 Advantix?

Experts recommend monthly application to keep your dog protected year-round.

My dog is strictly indoors. Should I still use K9 Advantix?

Yes, ticks and fleas can be brought into the home by people or other pets--without owners even realizing it. Immature flea stages remain dormant until conditions are appropriate for development. This is why it is also important to protect indoor pets.

Can I bathe my dog during the month after application?

Yes, you can give your dog a bath. A non-detergent shampoo is recommended for best results.

How young can the dog be for application?

K9 Advantix is gentle enough for puppies as young as seven weeks.




Imidacloprid is an ectoparasiticide, an antiparasitic agent that targets parasites living primarily on the surface of a host. Chemically classified as a chloronicotinyl nitroguanidine, imidacloprid inhibits neurotransmitter transmission in insects, resulting in paralysis and death.


Imidacloprid exhibits both adulticide and larvicidal flea efficacy; it not only kills adult fleas and larvae on your pet, but it also kills larval stages in your pet's immediate surroundings.

Main Purpose

To kill fleas at all stages of their life cycles and stop them from being able to move or feed.


Permethrin is the additional ingredient in Advantix. It belongs to the Type I class of pyrethroid acaricides and insecticides, and it also acts as a repellent. Pyrethroids affect muscle and nerve cells' sodium ion channels by increasing their mean open time, which leads to hyperexcitability and death of the parasite.


Thanks to its repelling activity, permethrin reduces parasite bites and thus the risk of diseases and stress for your dog.

Main Purpose

To repel ticks, sand flies, and mosquitoes; to kill ticks and fleas.

Two Proven Ingredients with Enhanced Activity

Imidacloprid and permethrin work together to overwhelm the nervous system of the parasite, providing neurotoxic activity beyond that of each compound alone. This leads to more profound and quicker insect paralysis and death.

Specifically, imidacloprid increases the efficacy of permethrin by activating insect nerve cells and increasing the frequency of neurotransmissions. As a result, more sodium channels are opened and the pyrethroid can interact much better with its target site.


Pyriproxyfen is a pyridine-based pesticide. A juvenile hormone analog, it interferes with the hormone signaling of growing insects, so that insects in immature stages are unable to mature. Additionally, a female insect that touches the toxin will produce eggs that will not hatch.


Pyriproxyfen provides an added layer of protection for pets and their surroundings. It interrupts the flea life cycle at multiple stages, halting the growth and development of insect eggs and larvae and preventing reinfestation.

Main Purpose

To prevent flea eggs from hatching and larvae from growing.

Active Ingredients % by Weight
Imidacloprid 8.80%
Permethrin* 44.00%
Pyriproxyfen 0.44%
Other Ingredients 46.76%
Total 100%
*cis/trans ratio: max 55% () csi and min 45% () trans
Net Contents

Six tubes, each 0.084 fluid ounces (2.5 milliliters)

12 MONTH K9 Advantix II TEAL for Medium Dogs (11-20 lbs)12 Mo K9 Advantix II (11-20lb)Reg price: $196.99
Sale price: $148.95
4 MONTH K9 Advantix II RED for Large Dogs (21-55 lbs)4 Mo K9 Advantix II (21-55 lbs)Reg price: $71.99
Sale price: $49.95
12 MONTH K9 Advantix II RED for Large Dogs (21-55 lbs)12 Mo K9 Advantix II (21-55lb)Reg price: $200.99
Sale price: $148.95
4 MONTH K9 Advantix II BLUE for Extra Large Dogs (over 55 lbs)4 Mo K9 Advantix II (55+ lbs)Reg price: $72.99
Sale price: $49.95
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Customer Reviews

DISCLAIMER: The results described on the testimonials on this site, are the individual experiences and personal opinions of those who have purchased and used the products. These testimonials are not intended to make any claims that the products can be used to diagnose, treat, mitigate, cure or prevent any disease or medical condition.
Click here to see all reviews
by from 05/15/2014

No more ticks! by HulaGirl from Kailua, HI10/30/2011

As always I received my Entirely Pets order quickly! We've been having problems with ticks this year and this seems to be the only product that helps.

Possible Problem by louie from Florida12/20/2012

Put product on pet and it really never dried and it appeared to bleach dogs hair. After several hours wet spots with soapy water and removed product. Not sure if it was bad product, where it was made or something on the dog. but for sure I wont be buying it again.

We love this! by Brittany from PA07/12/2011

I have a German Shepard/Boxer mix who weighs 39 lbs. I bought the 21-55 lb two months ago and it works great! He was on Revolution (which is a flea, tick, & heartworm med all in one) from our old vet and he was getting bit by fleas daily and had 10+ enormous sores from his front legs to his back legs, so we took him back to the vet - they claimed that he was bit by a beetle, so we took him to a new vet, and they said the Revolution wasn't working. Switched him to this - the sores all healed within two weeks and he's as healthy and as flea and tick free as can be and we live back in the woods with a pond!!

by Nancy from Greenville, New Hampshire11/07/2011

K9 Advantix is the only product I will put on my dogs. It is much better than frontline in that it protects really well

Fabulous Deal by shossy4 from Boynton Beach, FL05/30/2012

I searched on line for a discount website for flea/tick meds and found Entirely Pets. Their prices by far were the cheapest, the delivery very quick. I will definitely use them again. Thanks!

Best product on the market by TJ from Sumter, SC08/15/2011

I used Frontline, K9 Advantix 100 and Advantage before, not of them repelled ticks and I had to remove ticks every day after our hike in the woods. Some already attached. Since I have switched to the new K9 Advantix II, I very seldom find a tick attached to my dogs. I highly recommend this product and my dogs never had fleas or mosquito bites. This is the best product currently on the market.

Priced right by jam from Ohio03/07/2013

I ordered this product for my daughter and the price is cheaper by ordering through your company.

Sorely disappointed! by Dixieland from Irvington, AL06/26/2012

Prior to using this product on my jack russell, I had only found 1 flea on her so it's not like she was infested...then after applying this product on her and I did so exactly as directed, a few days later I find another flea! Now I am wary of this product doing what it is supposed to! If I ever need to replenish flea medication, I will probably try another brand.

Arrived promptly by jjmom from Asheville, NC12/17/2012

I ordered the product and it arrived in good condition and very promptly. I would recommend Entirely Pets to anyone who wants to order pet products on line.

by from 03/30/2013

this product does all it says. my dog has not had fleas or ticks on her at all. also, and this is great, in the summer the mosquitoes and flies esp. green heads, do not alight on her to bite; that is a real plus.

this by product!" from the best repellentI


Great product by Karen from Texas09/29/2013

Easy to use and very effective at flea and tick control-I have never seen any on my dogs

Do Not Buy This Product by concerned05/31/2011

The weight requirements are wrong. My 3 year old french bulldog is 23.5 pounds. After trying this product on 05/27/11 she has been to two vets, had 3 baths, and is on valium and muscle relaxants. She is still not back to normal. She is agitated/restless and her legs and head still jerk and shake. This product is way too strong for a dog on the smaller end of the range stated on the package.

Advantix - works well for my dogs by Sasksi from Roanoke, VA10/23/2012

I have used Advantix for a while and it works well for my dogs. I have 3 inside who also have access to an outside fenced run.

Overall, very good! by kat07/27/2013

But the biting flies still get them when they go out. It's Florida, you can't expect miracles.

by Sun Girl11/06/2012

Love this product! It really works & easy to apply.

K9 Advantix II and Entirely Pets Return Policy by Tracy D from PA09/03/2012

I have 2 dogs. This product did not work and one dog had a severe reaction and I have to take him to the vet ASAP. Not only is that an issue but the return policy at entire pets is not as good as 1800 Pet Meds. Entirely pets does not allow you to send back an opened box but 1800 Pet Meds does for 100% refund. I recommend 1800 Pet Meds and Frontline Plus which is what I was using before. Tracy

No fleas on our dogs by Annie Banannie from Falls Church, VA11/07/2012

The repellant properties of K-9 Advantix are why we continue to use this product. Our dogs are flea, flea egg and tick-free; mosquitos keep away too.

The best by Abby01/20/2013

We had used Frontline in the past, but the fleas became immune to them. We switched to Advantage, then Advantix because it is very effective. We had a flea infestation this summer because of a mild winter, so we had to fight them even harder. I think we finally have the fleas under control.

Great product by Claudia12/17/2012

Works great. Used to use frontline plus, but switched to K-9 advantix II

Works the Best by Maerzie from N.E. Wisconsin, and Gulf Shores, AL07/07/2012

I have been using Advantix for my pair of Beagles since they were old enough to be outside. They need a very effective flea and tick prevention medicine because they are frequently in the woods hunting.

Good stuff by foxhaven from MO12/08/2011

Vet recommended. What more can you ask for. Plus Entirely pets has the best prices that have found.

Doesn't last whole month by ellrig11/06/2012

This works up to a point, but doesn't seem to be effective for an entire month on our mixed breed. The other leading brand we've tried doesn't either.

Best Product Ever by Pinschermom from Apopka, FL12/01/2012

This is the best product for my German Pinscher who is terribly allergic to no see um bites.

by Ttixie from Pgh. PA06/28/2012

great product at the right price and super service and delivery

It works by Levic from Trinidad & Tobago07/03/2012

I use this monthly on my 3 dogs...different breeds and so far they have remained tick and flea free. Do note that we live in the tropics and my dogs live outdoors, so they are very susceptible to ticks, flea, flies and mosquitoes.

Excellent Product by brgunter from Columbia, SC04/23/2013

We find this product to be easy to apply; no greasy residue after application, no odor and does a great job for our two babies (adult cocker spaniels).

WHAT A DEAL! K-9 Advantix Red (6 month supply) by mortgage bob from Williamsburg, Ontario Canada07/09/2014

We've been recommended by our Vet to use this product as we are in a high tick area. I bought the product for years through the local vet. Just by accident, I was shopping Entirely Pets for dog treats when I came across the same product (K-9 Advantix) at half the price. Same stuff, same manufacturer, same dosage, same everything except the price. Been buying ever since at Entirely Pets!!!!!!

by from 07/03/2012

I am rather unhappy that now K9 Advantix II includes yet another perticide for lice. I do not have a problem with lice and don't like to treat for something unnecessarily. That is how insects become resistant to pesticides.

it by if from II


excellent tick and flea repellent by figaro jr from old lyme ct01/01/2013

I have used K9 Advantix II on my dogs for the last six years or so. We used Frontline Plus before and were quite happy with the results until one year it just did not seem to impact ticks. We live very close to Old Lyme (yes, of Lyme Disease fame) and needed a product that was more reliable in destroying ticks. Advantix II has been excellent. We highly recommend it.

Works well by Monica from Chesapeake, VA11/06/2012

We have been using this product for a few years and it works real well. We stopped having problems once we got our dogs on the Advantix program. The only thing is, the product is a bit pricey!

the best by gotti from ny05/09/2013

I only use this p[roduct and it works the best

Advantix 2 by Jeannie from Galway, NY04/16/2014

Great product. I have used it on my dog for 15 years.

good brand by missy and the cats ma from savannah, ga.07/19/2013

been using this brand for a while now. used to use front line....but , when I moved down south from Michigan to savannah, it wasn't enough coverage!!!! plus, I brought my horse down with me and , I noticed he would get the occasional tick, which he never got up north, even though we have ticks up there....so, I switched to K-9 advantix II, and no ticks on my long-haired dog! and no flea break-through in 2-3 weeks!!! entirely pets is the best source for your pets needs! the best prices and the fastest shipping!! no matter where I go, entirely pets goes with me!!! thanks a million

by BetsyBrady04/03/2013

I use this regularly and usually buy it from the pet store, but you had a very good sale on it so I bought two boxes from you.

This works and good value by Kiahlily from San Diego, CA06/27/2013

Never had a problem with fleas or ticks on my dogs while using this product.

by k905/29/2012

my dog still has fleas not as much and still scratches i'll look for another flea control to see if there is another problem with my dogs

It works! by Springer Mom from Freehold, NJ10/22/2012

Yes, I would recommend this product. It was told to change my flea & tick medicine for my dogs and this product is doing the job.

great product by linda-e from New Jersey09/04/2012

advantix II does what it says it will-repels fleas, ticks, as well as biting flies and mosquitoes of which we have many in the summer. I only wish we had this product when we had our other dogs in years gone by. highly recommend.

Not as good as original formula by sugar12/30/2012

Applied this product on my dogs every 30 days without fail all year. Over the summer, both of my dogs who used this product suffered from a severe case of fleas for several months.

by from 08/21/2014



had higher hopes... by breezy from Pittsburgh PA11/20/2012

After years of Frontline Plus which ticks seemed to be immune too now, and then two years of TriForce only to find its now discontinued, was extremely hopeful of K9 Advantix II plus it took care of alot more than flea and ticks...supposedly... A week after using on 2 dogs, I noticed one constantly scratching and biting at herself. The morning of the 2nd dose, I find that she has fleas all over her back end. ???? She's never had fleas before! My other dog, shows no signs at all. I put the second dose on the back of her neck and at the top base of her tail, hoping this kills things off. But if she starts itching again and i see fleas, I'm requesting a refund.

A must have product by Biscuit from TN06/29/2012

I wouldn't think of letting my pets go without K-9 Advantix II. No fleas or ticks on my dogs.

by from 11/06/2012

Great flea protection by far by Play07/03/2013

I've been using K9 Advantix, since my vet put my dogs on it. I've been very satisfied with this and have used it for the last 3 years. My dogs do well with it, and also do not itch like they use to when I used a different product. Entirely Pets has the best price for all my dogs needs.

Great value by kittenonkeys from Central Louisiana12/05/2012

K9 Advantix II is a product I find very useful in eliminating the flea and tick problem with my 3 dogs. Prior to using it and a similar product, I would get fleas in my house. This is no longer an issue. I will occasionally find a tick, but not to the extent prior to the product.

K9 Advantix II (21-55lbs) by Amber's Mom from Portland, OR12/15/2012

We hike in deep woods where there are ticks. My dog got a bad tick infection with flea prevention alone. Since using this flea/tick combo she's never had another tick on her. Works very well without the bad side effects I've read about with other products out there. She's 52lbs and this dose works great.

Not user friendly by ohlab02/10/2013

not like the one spot products runs and is very messy to use.

by mustang girl06/02/2012

use this product for both my dogs and I am very satisfied with it. We used another product and our dogs seemed to be very lethargic for a day or so after we applied it to their skin. They don't seem to be bothered by this product.

by puglover from Cutler Bay, Florida11/30/2011

Great product.. Really good price with this company....

Highly Effective by Daveo from Waco, TX01/11/2012

We have three English Springer Spaniels and made the switch from Frontline Plus to K9 Advantix ii because Frontline Plus was not working well. With Frontline Plus the fleas were back within a couple of weeks. After changing to K9 Advantix ii, not a single flea. I have been able to cut the application to every other month and still no fleas. We also have a cat that is constantly around the dogs. I keep him away while I dose the dogs and for a few hours afterwards. There has been no adverse effects. I think this is a highly effective product.

Doesn't Work for Long by Danielle06/28/2011

Thought this would be great since it repels and kills. I had this on my dog for about 2 1/2 weeks, then found 3 large ticks that had obviously been stuck on her for days. She didn't have any bad reactions to this, it just didn't work for very long. Went back to Frontline, it works for the full month.

No worries by Trumprider from Ohio12/29/2012

A bit pricey but works great. I'm happy, the dogs are happy. The best.


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