PetMeds® K9 Advantix: Flea Medication for Dogs

K9 Advantix is a flea medication for dogs only. Always wait until product is thoroughly dry before letting your dog be around cats.

K9 Advantix is one of the most common used once monthly topical pesticides used for external skin parasite control, covering fleas, ticks and mosquitoes. One of the nicer benefits is that it will still be effective even after washing and bathing (wait 24 hours after applying), and has additional benefits of not only quickly killing mature and immature fleas and ticks, but in also repelling these parasites from biting as well. It comes in very convenient dosing packaging for dogs up to 10 pounds, dogs from 11-20 pounds, dogs from 21-55 pounds, and dogs over 55 pounds.

If your pet is on the border of these dosage cut offs, you can always start with the lower dose of K9 Advantix, however, if effective pest control is not seen, than giving the higher dose is certainly safe in most pets. It is not necessary to separate dogs after dosing them topically with this product, however, if dogs are actively playful and/or licking one another, it may be best to have them apart for a few hours, until the product has had a chance to dry.

A few years ago, it was recommended not to purchase this product if an animal guardian also had cats due to their sensitivity to the permethrin insecticide in this product. However, that labeling has now changed and it is ok to use in households with cats, as long as animal guardians wait until the product is completely dry on the dog before exposing them to household cats.

I have not heard of its use in other species, although an animal guardian of exotic pets can certainly contact Bayer to find out if this is possible. Side effects are rare, but may include (in sensitive pets):

–          Contact irritation/allergy causing hair loss at site of application

–          Digestive upset

–          Neurological reactions such as seizures (rarer cases)

If this should occur, changing to a different topical pesticide like Frontline Plus or trying a natural alternative may be helpful. I never recommend using two topical pesticides at the same time such as Frontline Plus or K9 Advantix. However, if one is not working for an animal guardian, make sure one is treating the home adequately for fleas, as well as one could change from one product to another. It is typically not harmful to humans unless the product is swallowed or gets in one’s eyes. But I have heard of isolated reports of skin numbness following contact with the product, thus animal guardians should always wear gloves when applying this or any topical pesticide in my opinion.

Related Posts


  1. I absolutely concur regarding over the counter or non name . brand flea and tick topical products. My Mother purchased (by mail order) some kind of alternate product-and now both dogs are a mess of fleas and ‘itchies\. I never had a problem (even in Virginia, which seems to be the flea capitol of the world) when I was using the name brand products.
    Listen up people before you have dogs in agony like mine!

    • I agree with nina, when it comes to flea and tick control… you get what you pay for. I have only had luck with Advanitx products. I have not tried K9 Advantix II yet. I’ve always just used K9 Advantix because it works. Why change some that works!? is cheaper and you get free ones when you order. OTC items have been killing dogs or making dogs sick. I have not had any problems with this brand.

  2. Browsing on Google for something else closely connected, regardless before i ramble on too much i would just like to state how much I cherished your post, I’ve added your web blog and also obtained your Feed, Again thank you very much for the article carry on the good work.

  3. I agree with Nina. You think you are saving on generic or cheap dollar store brands but they either never work, halfway work or cause bad reactions. I am a vet tech and I only use and recommend K9 Advantix to patients. Even though my boss hates that I do it; I always tell patients to search for the best deal online. You can save a lot with all the competition online.

  4. Hi, I have a question, is it safe to use a topical flea and tick medicine (advantage) with an additional store bought flea collar? I am concerned that the dog may have adverse reactions with mixing flea and tick meds.
    My husband just applied a topical med. (advantage) last week to our 60 lb. Catahoola Leopard dog Koda. Today I found my dog with a flea collar around his neck. Any thoughts or suggestions would be appreciated.

    • Dr. Michael Dym, VMD veterinarianOctober 23, 2010 at 12:09 pm · Reply

      I would not use both as too much pesticide. Stick with advantage and treat home for fleas. Can use oral capstar and/or oral program if needed from 1800petmeds if heavy infestation

      • I gave my dog his last dose of frontline plus one 8 days ago and noticed it wasn’t working anymore. I have orderd the K9 advantix….how long do I have to wait before giving him the new stuff. The Capstar doesn’t work for very long and my pup is miserable. I hate to think he has to wait 22 more days before I can give him the new meds.

  5. The label on Advantix says not to touch your dog after it has been applied….but how long do I have to wait before I can hold and pet her? She is a little chihuahua that cannot sleep unless she’s under your blankets…so I want to know when it’s safe for her to be in my bed. Thanks!

  6. I bought k9 advantix and it says not get on skin but how long before I can touch my dog after applied?

  7. I just purchased the new Advantix II, I have two large dogs and i have always used Advantix on them. After i applied this new product i noticed one of my dogs started acting very strange, he started panting and acting very irritated. He keeps moving around and wont lay still. My other dog seems to be fine, and she is acting normal. Im not sure what is going on or what to do with him. Like i said i have always used Advantix and this has never happened before.

    • Dr. Michael Dym, VMD veterinarianApril 7, 2011 at 9:34 pm · Reply

      There is extra ingredient in the advantix II that may be causing the reaction in your pet. Every animal is a unique individual. I would change back to advantix or go to front line

  8. I just picked up my dog’s next heart worm pills and was told by the folks there that my vet does not recommend flea and tick collars. Then I saw all these horrors stories posted online about dogs getting really sick or dying from Hartz collars. I just took it off my 65lb lab puppy. How long should I wait to put the k9 advantix on him and is there anything else I should do? He has worn the collar for about two weeks..we did notice he doesn’t eat like he was eating before…and drinks a lot more..but then it has been really hot here lately…..

  9. I have been using advantix on my pomeranian since she was a pup with no problem. Now the last two months she has been having fleas. I just put drops on her two weeks ago and she had enough fleas that the groomer had to give her a flea bath. I am thinking of switching to frontline plus to see if she could be getting immune to the advantix. How long will I have to wait till it is safe to put the frontline plus on her. She still has fleas. I also bought capstar. When is it safe to give her any more meds?

    • Dr. Michael Dym, VMD veterinarianJune 11, 2011 at 3:16 pm · Reply

      You can wait 2 weeks after last topical flea application to change to different brand. Remember to also treat the home environment as well which is where much of flea life cycle occurs.

  10. I applied K9 Advantix II 10 pounds and under to my dog. My daughter did not know I had already done it and I discovered that she put some on him later that same day. So he was double dosed. Do I need to do anything?

    • Dr. Michael Dym, VMD veterinarianAugust 1, 2011 at 11:49 am · Reply

      I would try and wash dog however product is supposedly water proof. Most likely your dog will be fine. I would just monitor and observe for any lethargy or digestive upset, etc

  11. I applied K9 Advantix to our Jack Russell 3 weeks ago and I think I have seen a flea or 2 in the last 2 days. Is it OK to reapply even though a full month has not passed? She is a small 12 lb dog. Also, it is hard to really separate her fur completely when applying it because her fur is so short. The flea med. does get on her fur. Does that matter and could that effect the absorption of the med.?

    • Dr. Michael Dym, VMD veterinarianAugust 6, 2011 at 12:41 pm · Reply

      Not applying the product completely on the skin can affect absorption and sometimes efficacy. I have had clients use the product a week early so go ahead and reapply. Also make sure to treat home environment of pet where much of flea life cycle occurs.

  12. Pingback:   K9 Advantix II four Pk Blue Dog Over 55 lbs.|Cheap Pet Supplies

  13. Hello-

    How long has Advantix II been used on dogs? Is there any research on the safety of the product?


    • Dr. Michael Dym, VMD veterinarianApril 9, 2012 at 8:27 pm · Reply

      Advantix II has been on the market a few years. I would check with the Bayer company who manufacturs it on safety studies.

  14. Hi,
    I have a dog and two cats. Earlier today I applied K9 Advantix to the dog and wonder how long I have to keep her from her feline brothers? I worry they will attempt to lick her spot. Is it safe to put a little cotton tshirt on her for 24 hours so that the cats can’t get to her?

    Thank you!

    • Dr. Michael Dym, VMD veterinarianMay 6, 2012 at 1:45 pm · Reply

      A cotton teashirt would be fine for 24 hours to prevent cats from contacting the product.

  15. I use K9Advantix on my dogs. My lab weighs 133 lbs. After 2 weeks, he has fleas again. I have a dachshund who weighs 10 lbs., who I also use the K9Advantix on. When my lab gets fleas, they go onto her too after 2 weeks. Why doesn’t this stuff effectively eliminate the fleas for the whole month? I only started using the K9Advantix because it was the only one with tick repeallant, but I took two ticks off of him and he even got lyme’s disease. I feel like I am wasting my money.

    • Dr. Michael Dym, VMD veterinarianJuly 20, 2012 at 5:27 pm · Reply

      Sometimes during heavy infestations, the product needs to be applied more frequently. Also could try another product such as certifect

  16. I was given advantage 20 for11-20 lbs. Can I use less for my 5ish pound chihuahua and more for my 85 lb retriever?

  17. I just started my dealing with resolving my flea problems today (i have had an issue for about 2 weeks) before I put the advantix on my 20lb dog what can I use to help her with her discomfort (itching from bites) then what can I do to help her once i start the advantix?

    • Dr. Michael Dym, VMD veterinarianAugust 16, 2012 at 2:40 pm · Reply

      TRy oral benadryl at dose of 1 mg per pound twice daily and add fatty acid like missing link to meals from 1800petmeds which may help long term.

  18. How long after applying k9 advavntix II can my animals be allowed on the furniture

  19. I bought Advantix II for my dog, but I bought the 55 lbs + dose and weighed her at 50 lbs. Is it safe to give her the 55 + dose or should I return it and buy the lower dose?

  20. I have two small dogs, which I bought K9 Advantix II for (10-20 lb dosage). I have a large lab who weighs around 90 lbs. Is it safe to give the large dog 3 doses of the small dogs’ meds?

  21. I but the K9 Advantix II on my dog last night. She stays at my nephew’s in the morning (doggie day care). He has 2 yound children. It is safe for her to be over there with the children, or is the product dry enough for her to be around the kids?

  22. I used K9 advantrix II for medium dog two weeks ago, it seemed to work for a while and now he’s loaded down with them again. What can I do?

  23. we gave our dog the regular dose to get rid of fleas from her vet. am i right in brushing her after 1 week 1/2 she still has fleas. my husband says i shouldn’t brush her. who is right ? should i continue and leave them on her or brush her and continue to remove at least 7 fleas a day from her?

    • Dr. Michael Dym, VMD veterinarianJuly 8, 2013 at 11:56 pm · Reply

      Brushing is fine. I would just consider using additional flea meds like comfortis from 1800petmeds.

  24. I just gave my dog his first foe and tick dose of Advantix II

    1) How long does it typically take to dry enough that I can hug and kiss him again?

    2) I was planning on giving him his bath next week. Will this weaken the affects of the Advantix?

    • Dr. Michael Dym, VMD veterinarianAugust 11, 2013 at 9:40 am · Reply

      Once product dries within a few hours, should be able to kiss him. Bathing one week from now is not a problem.

  25. Simply desire to say your article is as astonishing. The clearness in your post is
    simply spectacular and i could assume you are an expert on this subject.
    Well with your permission allow me to grab your RSS feed to keep up
    to date with forthcoming post. Thanks a million and please continue the rewarding work.

  26. I am confused, the homeopathic vets say NO pesticides, unless the flea/tick infestation is extreme.

    The specialist that sees my 9.5 pound poodle says to do Advantix II on the 1st of the month, Revolution on the 15th, 2 pesticides per month?

    This sounds like too much, so I am going to continue monthly Advantix II, occasional Amitraz collars and Heartguard (which I give every 6 weeks) annual testing.

    Brewers yeast and garlic tabs, BugGone spray, frequent bathing. Frequent checking and avoidance of tall grass/brush, NO woods.

    I lost one dog to Lyme (kidney damage) years ago.
    I also had 2 test positive but never had any symptoms.
    The ticks are moderate too bad in my area.

    What do you think of my plan?

  27. Thanks, Dr Dym, I have ordered the Wondercide and will use it in conjunction with Advantix II and the other natural remedies I mentioned.
    The homeopathic vets advise to stay away from Revolution, so I’ll continue with the Hearguard every 6 weeks (3 seasons) and annual testing.

  28. Is it normal for my 10lb yorkie to scurry around the day I apply the the K9 advantix II? He typically does this only on the day of application. He seems restless and can’t stay still too long, hides and rushes from place to place.

    • Dr. Michael Dym, VMD veterinarianJune 29, 2014 at 4:18 pm · Reply

      This is not normal and is a reaction to the topical advantix. I would NOT continue to use it, as I would be concerned about long term effects on the body. Consider different topical such as revolution or changing to oral medicine.

  29. I put k9 advantix on my dog on Wednesday night around 9:30 I gave my dog a bath this morning (Saturday around 10:30). I’m worried I bathed him too early is that true? And if so is the medicine going to be in effective now?

    Any help would be great!

  30. I have two German Shepherd Mix dogs. One is 56 lbs, one is 50 lbs. I have a few questions.
    1) Should I dose them both at the up to 55lbs, or the 56 lb dog at the 55+ lbs dose or…?
    2) I just moved to Florida from MN and have never dealt with fleas before. I bathed them in a flea and tick shampoo about two hours before applying K9 Advantix II. Is it still effective? I have picked about 20 fleas off of each them today, which is almost a week after application. When can I apply another dose?
    3) How do I treat the home/yard? I know this is an important step, yet I haven’t heard a safe solution.

    • Dr. Michael Dym, VMD veterinarianAugust 6, 2014 at 7:59 pm · Reply

      There are yard and kennel sprays you can buy from local hardware stores. Some vets do carry yard sprays as well. You could also speak to gardner or exterminator as well for expert treatment. As for reapplying the advantix, I would wait a few more days, and then reapply. I usually dont recommend bathing 2 days before or after application. As for dosing, I think the 33 pound dose is fine for both dogs.

  31. I have tried both frontline and advantix on my 70lb lab pit mix. They work great for fleas but they are making him sick. He has severe upset stomach and pukes alot. We have since stopped and the symptoms quit. Are their any other flea meds we can try? We are currently bathing him weekly and put cedar chips out to help keep fleas away but not working the same.

  32. I used K9 Advantix on both of my dogs 8/29/14 according to their weight. Both were again infested with fleas one week later. Today, nine days later, 9/7/14, I put Sergeant’s Gold Flea & Tick collars on both of them 8 hours ago and they both seem to be fine, sleeping comfortably and no longer itching like crazy so I took the collars off. When can I put the collars back on and leave them on? Thank you.

    • Dr. Michael Dym, VMD veterinarianSeptember 8, 2014 at 3:31 pm · Reply

      You can put collars back on at any time

      • Thank you so much! My dogs will sleep comfortably tonight and so will I! You go above and beyond your call of duty; I wish you were a vet in my area, Concord, California; we would love to have you here if you ever want to relocate!

  33. Pingback: Can K9 Advantix Make My Dog Sick | Doggy Diarrhea

  34. I have 2 shit-zu mixes weighing 17 and 20 pounds. Can I give both dogs the k9 advantix for 21-55 pound dogs?

  35. I am a nursing mother and got this product on my hands. I washed them shortly after. Is it safe to continue to nurse my baby? I am worried this product is absorbed into my skin

  36. Brit, This is nasty stuff! Call your local hospital emergency room and ask for the advice nurse if Dr. Dym doesn’t get back to you soon. He usually relies within 12 to 24 hours, but your situation is somewhat urgent (in my mind.) You are probably fine, but why risk it? Good luck to you and your little one!

  37. Hi, I went online and bought advantix for dogs ten pounds and under I have a shih tzu who is 15 pounds. Will it work fine or should I apply two of the viles?

  38. 3 days ago we found our mini schnauzer (25lbs.) had a few fleas crawling on him. He had no flea bites that we could see. We bathed him, and applied K9 Advantix II for 21-55 lb. Dogs. 3 days have passed. He has about 5 flea bites that we can see, and whenever we check him we are able to see a couple of fleas. 1) at what point should we stop seeing fleas? 2) can we apply a second dose of advantix, and how soon? 3) Since I am seeing 1-2 fleas at a time would that be indicative of a flea problem in the house? Thanks in adavnce!!

    • Dr. Michael Dym, VMD veterinarianDecember 25, 2014 at 10:04 am · Reply

      I have found this product not always as effective as it used to be. I would consider using oral comfortis from 1800petmeds, and I would certainly recommend treating the home.

  39. My dogs neck is irritated and is now losing hair after putting K9 flea medicine on it. What should I do?

  40. I have a Schnoodle and have been using K9 Advantix Il for years with no issue. Tonight when I applied the treatment almost immediately a deep burgundy/dark purple stain appeared on her fur above her tail on her back. This happened once before last year and eventually it faded away but I was wondering if anyone has heard of this issue. She seems fine and like I said I’ve always used the same K9 Advantix ll. The stain appeared in only one spot where the treatment was applied but not on the other areas on her back where it was also applied. Strange.

  41. I give my dog advantix11 and he does well on it do I still have to give him a heart worm medicine because he a seizure 2 days after giving him sentinel

    • I would discuss these concerns with your local veterinarian as the decision to use heartworm medicines in a dog prone to seizures will be based on the actual risk in your area. There are also other options for flea and/or heartworm medicine as well such as prescription topical revolution

Leave a Comment

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>