Flea Meds Dosage Chart

Flea Med Dosages for Cats & Dogs

By isak, September 25, 2016

Updated: November 2021.
I have dosed down flea meds for years and, knock on wood, have had no problems. Having several cats and dogs, this is the most economical way for me to do it. With all the cats and dogs there are in the world, HOW can flea meds be SO expensive? I recently came across this chart of dosages for several of the most common brands of flea meds and am reprinting it here for anyone else needing it.

Ask your vet for the correct dosing and medications for YOUR animal. This list is just a reference guide and is not intended to avoid veterinary guidance or advice.

Advantage & Advantage II (Imidacloprid)

Advantage required adult fleas to ingest the medication, at which point they would be impacted by the insect-specific neurotoxins and die. Advantage II kills fleas on contact, with the addition of three new chemicals to its formula, that makes your dog or cat’s skin an entirely inhospitable environment for pests. Eggs are killed before they hatch. Adult fleas are killed and will fall off, or will be washed off in your dog’s next bath.

Kittens and puppies must weigh at least 2 lbs AND must be at least 8 weeks old to use Advantage II.

Dog Product Insert   |   Cat Product Insert

Dose is 0.05ml/pound. Multiply 0.05 times your pet’s weight for more precise dosage.

Advantage & Advantage II (Imidacloprid)
General guideline for lower doses.
Weight Dosage
Kittens/Puppies 2-5 pounds 0.23 ml
Cats/Dogs 5-9 pounds 0.4 ml
Cats 10+ pounds 0.8 ml
Dogs 11-20 pounds 1.0 ml
Dogs 21-30 pounds 1.2 ml
Dogs 31-40 pounds 1.6 ml
Dogs 41-50 pounds 2.0 ml
Dogs 51-60 pounds 2.4 ml
Dogs 61-70 pounds 2.8 ml
Dogs 71-80 pounds 3.2 ml

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Frontline Plus (Fipronil & (s)-methoprene)

Dog Product Info   |   Cat Product Info

The dose is 0.0305ml/pound. Multiply 0.0305 times your pet’s weight for more precise dosage.

Frontline Plus (Fipronil & (s)-methoprene)
General guideline for lower doses.
Weight Dosage
10 lbs 0.3 ml
15 lbs 0.45 ml
20 lbs 0.6 ml
25 lbs 0.75 ml
30 lbs 0.9 ml
40 lbs 1.22 ml
50 lbs 1.5 ml
60 lbs 1.8 ml
88 lbs 2.68 ml
90 lbs 2.7 ml
133 lbs 4.0 ml


NOTE: If you’re using Frontline Plus —
The amount of fipronil in the dog version is the same as in the cat version. The “Plus” is methoprene, an insect growth regulator. There’s LESS of it in the dog product than in the cat product, so it’s safe to use the dog product on the cats but do NOT use the cat product on a small dog.

Generic Frontline Plus for dogs may contain a different ingredient than the brand name. If a generic Frontline product contains something other than methoprene or fipronil it may not be safe on your cat.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Frontline Shield (Fipronil, Permethrin, & Pyriproxyfen)

The dose is 0.05ml/pound. Multiply 0.05 times your pet’s weight for more precise dosage.

Frontline Shield (Fipronil, Permethrin, & Pyriproxyfen)
General guideline for lower doses.
Weight Dosage
10 lbs 0.5 ml
15 lbs 0.75 ml
20 lbs 1.0 ml
25 lbs 1.25 ml
30 lbs 1.5 ml
40 lbs 2.0 ml
50 lbs 2.5 ml
60 lbs 3.0 ml

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Revolution (selamectin) / Stronghold

Revolution® has a single active, safe in both cat and dog, but it’s concentration varies: the formulation for puppies, kittens and cat is half strength. If splitting a large dog vial and applying the volume stated on the packaging for a cat, a double dose would be given. Take careful note of the half volumes shown below (concentration: 60mg/ml vs 120 mg/ml. Concentration amount is shown on the package.).

Product Insert

(General guideline based on 120mg per 1ml potency*Dose is 0.025ml/pound. Multiply 0.025 times your pet’s weight for more precise dosage.

Revolution (selamectin) for Dogs
Weight Dosage
0.0-5 lb dog/cat 0.12 ml
5.1-10 lb dog/cat 0.25 ml
10.1-20 lb dog/cat 0.5 ml
20.1-40 lb dog 1.0 ml
40.1-85 lb dog 2.0 ml
85.1-130 lb dog 3.0 ml


(based on 60mg per 1ml potency*. Dose is 0.05ml/pound. Multiply 0.05 times your pet’s weight for more precise dosage.)

Revolution (selamectin) for Cats
Weight Dosage
Up to 5 lb cat/dog 0.25 ml
5.1-15lb cat 0.75 ml
  • Potency/concentration is noted on the packaging.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Advantage Multi

 *Dose is 0.045ml/pound. Multiply 0.045 times your dog’s weight for more precise dosage.
The recommended minimum dose is 4.5 mg/lb (10.0 mg/kg) imidacloprid and 0.45 mg/lb (1.0 mg/kg) moxidectin, once a month, by topical administration

Product Info For Dogs   |   Product Insert for Dogs

Advantage Multi
Dog’s Weight Dosage Imidacloprid Moxidectin Product
3-9 lbs 0.4 ml 40 10 Advantage Multi 9
9.1-20 lbs 1.0 ml 100 25 Advantage Multi 20
20.1-55 lbs 2.5 ml 250 62.5 Advantage Multi 55
55.1-88 lbs 4.0 ml 400 100 Advantage Multi 8

~~~~~~~~~~~ ~~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~~
*Dose is 0.045ml/lb. Multiply 0.045 times your cat’s weight for more precise dosage.
The recommended minimum dose is 4.5 mg/lb (10.0 mg/kg) imidacloprid and 0.45 mg/lb (1.0 mg/kg) moxidectin, once a month, by topical administration.

Product Info For Cats   |    Product Insert for Cats


Advantage Multi
Cat’s Weight Dosage Imidacloprid Moxidectin Product
2-5 lbs 0.23 ml 23 2.3 Advantage Multi 5
5.1-9 lbs 0.4 ml 40 4 Advantage Multi 9
9.1-18 lbs 0.8 ml 80 8 Advantage Multi 18

*dosage is approximate. My math calculations came out to be 0.05ml/lb, but there is a discrepancy with packaged dosages. Also there is more Moxidectin in the dog formula than in the cat formula, so I would not put the dog product on cats.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


NEVER USE THIS ON CATS. If you get Advantix® on your hands when splitting a vial for the dogs, do not touch your cat before thoroughly washing your hands with warm soapy water. Advantix causes permethrin toxicity in cats because they cannot metabolize the permethrin in Advantix. More info permethrin toxicity.

(Dose is 0.04ml/lb. Multiply 0.04 times your dog’s weight for more precise dosage.)

Weight Dosage
0-10 lb dog 0.4 ml
11-20 lb dog 0.8 ml
21-30 lb dog 1.2 ml
31-40 lb dog 1.6 ml
41-50 lb dog 2.0 ml
51-60 lb dog 2.4 ml
61-70 lb dog 2.8 ml
71-80 lb dog 3.2 ml


Using K9 Advantix II? Here’s a list of generic alternatives to help you save money.

Flea Allergic pets, like those of us allergic to mosquito bites,  will incessantly itch and pull out all their hair if just one flea gets past the flea control. Given most spot on agents only achieve high kill rates, above 95%, for the first 2 weeks of the month, twice monthly application is often recommended by dermatologists when treating flea allergy.

Storage of Unused Topicals

Manufacturers packaging protects the product from 2 important things: light and air. Drugs and insecticides can be destroyed and rendered ineffective if mishandled. Keep in the vial and store in a cool, dark place. The fridge is ideal, but under the sink or any other ‘chemical repository’ is ok.  Do not freeze. You may also decide to keep the entire flea medication in the syringe itself which is fine but far from ideal. I recommend an airtight glass vial.  The key point is no air exposure, no light, and no heat and they will last a very long time.

reprinted from Starlight Boston Terriers, Global Watchdog, and others.


  1. Angel says:

    Could you please post a dosage chart for the K9 advatix II? I’m presuming it’s safe to split like the other meds. I’ve never used it before and I want to get it correct for my pups. Thanks so much for providing such useful info!!!

  2. Carrie says:

    Hello, I was wondering if you could give more information on advantix ll, you have it on here but the actual amount per pound etc.. isn’t there like with the other medications. If you could possibly post that in the chart as with all the other flea medications it would be greatly appreciated.

    I just wanted to say thank you again for doing this, keeping it going, thank you so much for always responding and so quickly it truly means the world.

    Quick note, ***** Reminder, DO NOT bathe your animal 2 days before or 2 days after you apply topical flea medications. For proper absorption it needs your animals natural body oils*****

    Keep up your amazing work!! God bless

    • isak says:

      Done. In general, you take the maximum weight in the chart’s row — for example, on the first row of Advantix, the maximum weight is 10 pounds, then divide the dosage — in this case .4, by 10 pounds. .4 ÷ 10 = .04/lb. This is the amount per pound.

  3. Laela Renee Roush says:

    Thank you for suggesting PuppyButts Quick Caps. Do you prefer the capsules or the tablets? Also, do you purchase larger doses and break them down into smaller doses according to weight as well?
    Going back to my original post on 10/29/21, I gave them .5 mg, not .05, my bad. So i think I will give them .75 this time. I will order those Quick Caps too for the next infestation ugh! Thanks again 🙂

    • isak says:

      The tablets are so small that I go that route. At this point, I only use them on my dogs which are 65+ lbs. So they take a full tablet. I recently adopted a 13 lb dog so I break one of the tabs down for her. I think these tabs are great to have on hand.

  4. V73V7 says:

    Hello and thank you everyone for all your helpful hacks! I have an issue I was hoping someone reading might share their insight. I use Advantage II xtra large breed for my 100+lbs GSD, 55 lbs Chow Chow, 10 lbs Pom, and 13 lbs Pekingese. I gave the 2 little ones too low of a dose .05 and they are still itching like crazy after 2 weeks. How soon can I re-dose, and if it’s before the recommended 3 to 4 weeks, should I half the dose, or use the proper amount?

    • isak says:

      It seems that these meds only work for about 3-3 1/2 weeks for me, so I re-apply at about 3 1/2 weeks. Before applying, I give them a QUICK CAPS (Nitenpyram) to treat any existing fleas, then apply the topical flea meds.

      As for your situation, if you gave your small dogs .05, that’s the dose for 1 pound, so you should be fine giving them the full dosage they need (.05 x their weight in pounds).

      Puppy Butts has a great price on QUICK TABS, if you’re interested.

  5. Kady says:

    Hi! I read through everything and really appreciate you doing all this. Thank you ??

    My question is about dosing bravecto. I have bravecto for large dogs though cannot figure out how to dose that to all my foster cats. Above in the comments you say mg/lb though I don’t know how to translate that to ml/lb. If you have suggestions on how to do the math I can probably figure it out.

    Thank you again!!!!

    • isak says:

      The general rule of thumb is to determine how much to dose per pound. For example, the Purple Bravecto for cats has a max weight on the label of 27.5 lbs. Each tube contains 500 mg of Fluralaner. 27.5 divided by 500 = .055 ml/lb. So if you have a 10 pound cat, the dosage is .055 x 10 = .55ml.

      If you are using the Bravecto for dogs on your cat, I would still use the cat scale in the example above. The dosage for dogs seems to be slightly higher. They are dosed at ~.09 per lb.

  6. Carrie says:

    Thank you so much for continuing to keep this information out in the world, I have been telling people this for years. Everything is ridiculously expensive already and the cost will only continue rise making it harder and harder to survive. Anyway possible that can save people money especially when it comes too our beloved fur babies, we must yell and scream it loudly for all to coast to coast.

    Just an FYI so I have my own animals and we still and have always rescued many animals over the yrs and I have always parted out flea/tick meds. It wasn’t until a few yrs after doing this that I found out one very important piece of information which I wish I would’ve know many yrs before ummm… like… possibly … “WHEN I FIRST STARTED USING IT!!!!” Just saying!!!

    When you are going to give your animal flea/tick medications(liquid only) you MUST:
    Make sure you do it 3 DAYS BEFORE or 3 DAYS AFTER A BATH!!! The natural oils on your animals skin are needed in order to help them properly absorb the Flea/Tick meds. This is the difference in how affect, how fast acting and for how long lasting it works for your fur babies. (**Trust me when I found this information out my mind was truly blown**). Good luck too everyone! And please keep up the great work your doing, I greatly appreciate it.

  7. Tabby says:

    Do you have a suggestion for dosing a 28 pound maine coone? Large cat flea treatments just last a couple weeks at most and then he is miserable again. I have been getting revolution from our vet.

    • isak says:

      Wow, 28 pounds! That’s a LOT of cat!

      If you want to continue using Revolution, you could buy the dog version and dose it down. It’s twice the potency of the cat version: 120mg per 1ml potency (dog) vs 60mg per 1ml potency (cat). You multiply the weight of your cat by 0.025 to get the dosage on the dog version, so 28 x .025 =.7ml. I buy mine online from Sierra Pet Meds.

      You might give your cat a Quick Tab before the Revolution. Quick Tabs contain Nitenpyram and starts killing fleas in 30 minutes. That might help. I buy those from Puppy Butts.

      I agree with you that the flea meds these days seem to only last 2-3 weeks. And the meds are certainly not cheap.

  8. Laura Finney says:

    I have read the entire post and I cannot find the dosage for Frontline Shield. Would it be the same as Frontline Plus?

    • isak says:

      The dose for Frontline Shield will be a tad higher than the dosage for frontline Plus.

      The general rule of thumb for dosing down is to divide the ml per vial to the largest weight that vial covers because the flea med producers want to make sure even the biggest dogs in the range of their product are adequately dosed. So if you divide the vial quantity by the largest animal size in pounds for each size category, you get 0.05 ml per pound for Frontline Shield.

      For example, if you buy the extra large Frontline Plus (89-132 lbs), it comes in 4ml vials. If you divide 4 by 132, you get .0303ml. This is how much Frontline Plus to apply per pound. 10 pound dog x .0303ml = .3ml.

      The math for Frontline Shield: extra large Frontline Shield (81-132 lbs) comes in 6 ml vials. If you divide 6 by 132, you get .045ml. The math on the smaller sizes (large, medium, small, extra small) comes in at .05ml per pound. 10 pound dog x .05ml = 2ml.

      Hope that makes sense.

  9. Rochelle says:


    Your Revolution dosage information for cats is wrong. I don’t know if it’s the math you used or what, but to take large dog version to cat dosage is:

    0-5ish 0.18 ml, 5-15ish is 0.38, and large cats are 0.5. Our shelter had a veterinarian dose it. We then chose simple to remember directions. Kittens 0.2 ml. Adults up to 10lbs 0.4 ml. And big cats at 0.5.

    Even double checking with Maddie’s Fund shelter medicine page has them at those numbers.

    And Advantage Multi for dogs CAN be split for cats. I know a vet who does it a few towns over. But I’m trying to get accurate dosage information per lb and no one has it! ????

    • isak says:

      Thanks for your input.

      What is the potency of the Revolution you are basing your calculations on? 120mg per 1ml potency or 60mg per 1ml potency?

      If you are dosing down the dog version (120mg per 1ml potency), your numbers are similar to what we show in the top table. The bottom table for Revolution in the post is based on dosing down the cat version of Revolution (60mg per 1ml potency).

  10. Bonnie L Wallen says:

    Is there a dosage chart for Bravecto for extra large dogs to cats? I have 30 rescue cats that I need it for.
    Please help.

  11. Dina says:

    I recently discovered Activyl due to my other monthly flea go-tos no longer working at all against fleas. I have not purchased or used Activyl yet, but am doing my research currently on dosing for dogs and cats. It appears that the formula for both dogs and cats, are the same, as is the case with Frontiine and Advantage (which is what I was using). I have always multidosed my 11 rescue cats and one small dog with the large dog treatments (broken down in the correct dosages per their weight). I was having a hard time findind the correct dosing for Activyl, so after some googling, I found this list that I thought I would share, since it seems many others have the same question. These are the standard doses that come in the pipettes purchased in the boxes, not exact dose by weight, but I think this should be a good guide for dosing.


    Dogs, small <6.5 kg ? 15.0 mg/kg indoxacarb)

    Dogs, medium 6.6 to 10 kg ?14 to 22 lbs. bw: 1 pipette with 0.77 mL (equivalent to 22.8 – 15.0 mg/kg indoxacarb)

    Dogs, large 10 to 20 kg ?22 to 44 lbs. bw: 1 pipette with 1.54 mL (equivalent to 30.1 – 15.0 mg/kg indoxacarb)

    Dogs, very large 20 to 40 kg ?44 to 88 lbs. bw: 1 pipette with 3.08 mL (equivalent to 30.1 – 15.0 mg/kg indoxacarb)

    Dogs, extremely large 40 to 60 kg ?88 to 132 lbs. bw: 1 pipette with 4.62 mL (equivalent to 22.6 – 15.0 mg/kg indoxacarb)

    Cats, small <4 kg ? 24.9 mg/kg indoxacarb)

    Cats, large >4 kg ? >8.8 lbs. bw: 1 pipette with 1.03 mL (equivalent to <50.3 mg/kg indoxacarb)

    * Can be slightly different in some countries: read the product label!

    Source: https://parasitipedia.net/index.php?option=com_content&view=article&id=2766&Itemid=3086

    • isak says:

      Thank you.

      My guesstimate would be something like .05ml per lb. For example:

      .05ml x 10lbs = .5ml of Activyl
      .05ml x 55lbs = 2.75ml of Activyl

  12. Julia says:

    Anyone have the correct dosages for Activyl for Dogs?
    It seems to work better for us, but I am never sure if I am putting the right amount/too much/too little.
    We have 6 dogs on our farm from 10# – 55#

    • isak says:

      I’m sorry, I don’t know the answer for sure, but looking at their boxes, my guesstimate would be something like .05ml per lb. So…

      .05ml x 10lbs = .5ml of Activyl
      .05ml x 55lbs = 2.75ml of Activyl

      What amounts have you been using?

  13. Marilyn G says:

    Thank you so much in your comprehensive and common sense approach to assisting animal lovers in being able to afford the best care for their pets. We used to have a vet that was helpful with converting livestock meds into appropriate smaller animal dosages.
    For an example: Quest Plus Horse paste wormer, for most breeds of dogs, divided up makes a very efficient tape/wormer that is much less expensive and much more obtainable.
    Do you have other med-dosages that you share online?
    Currently I use Ivermectin Horse for basic worms in all our adult dogs and pups over 8 wks (Golden retrievers)by mixing with corn oil 6-1 ratio and dosing at 1ml/15#. I plan to follow your posts and hope to continue to read great information from you!

    • isak says:

      Thanks for your input. It’s much appreciated. Corn oil — that’s a good idea.

      We’ve backed off discussing the use of Ivermectin Horse Wormer for dogs because it can be toxic for some dogs, and that toxicity is generally not reversible. There is a list of dog breeds deemed most sensitive to the product, but the toxicity has also been seen in mixed-breed dogs, older dogs that have experienced a blow to the head, puppies, and dogs that have overdosed on similar types of drugs. That’s quite a list. So given all that, we don’t promote it.

      That being said, I did treat my rescue dogs — they were mostly mixed breeds — and cats for years with Ivermectin horse wormer with no problems (knock on wood).

      Again, thanks for your input. I’ve added your dosing recipe to the bottom of this post.

  14. Hannah says:

    K9 Advantix II
    Why do these recommendations not line up with the manufacturer dosages? How were the dosages on BeingStray decided?

    10 lbs. and under 0.4 mL (Green)
    11 lbs. – 20 lbs. 1.0 mL (Teal)
    21 lbs. – 55 lbs. 2.5 mL (Red*)
    55 lbs. + 4.0 mL (Blue*)
    *Use several spots for a larger animal to avoid irritation.

    • isak says:

      I think you are comparing K9 Advantix and K9 Advantix II. K9 Advantix is considered the original version of the product. To improve the formula, Bayer added pyriproxyfen, an Insect Growth Regulator. This addition results in the termination of all life stages of the flea whereas Advantix is only effective at eliminating adult fleas.

  15. Ella says:

    So happy I found your site. We have inside rescue cats ranging 1 year-16 years old… a couple ran outside over the summer and we’ve been finding some worms when scooping the litterboxes… So treatment for everyone since they share several boxes.
    Previously our vet down-dosed using Advantage Multi Dog, but now says to just use Revolution Plus Cat/weight ($230 for 1 month treatment!) According to your chart for Advantage Multi, it reads that you DO NOT recommend for cats: “Also there is more Moxidectin in the dog formula than in the cat formula, so I would not put the dog product on cats.”…. Is this still the case- that you would NOT use a down dose Advantage Multi Dog for your cats? If not, what do you use for fleas/multi-wormer/ear mites and the calcultations?

    Down dose info from our vet are spot on with your calculations:
    DOG-Advantage Multi for cat/ lb:
    2-5 lb = .25 ml
    5-9 lb = .4 ml
    9-18 lb = .8 ml

    Do you know of Depo Medrol/options for an elderly cat that will vomit without a monthly shot($25/shot/month)? – when I call they say ‘we’ll make up your depo allergy shot’, so I was wondering if that is something I could affordably do?
    Thank you for a wonderful site of useful information to help us afford loving all the fur babies!

    • isak says:

      I am answering in no specific order, so please bear with me.

      Depo Medrol is Methylprednisolone acetate, correct? So it is a more potent (and injectable) version of prednisolone. Will prednisolone work? Both medications are for reducing inflammation. I don’t understand the link to vomiting that you mention.

      There is a topical flea product called Stronghold which is the same as Revolution but less expensive, in both dog and cat formulations. I buy my Stronghold from a company called Sierra Pet meds. They have several offers and sometimes throw in a free tube or two, but shop around and find the best price for you. Stronghold/Revolution handles fleas & heart worms, intestinal parasites, ear mites and worms. The largest dog size comes in a 2 ml tube, but the strength is 240 mg of selamectin so the dosage would be .0125/lb.

      Advantage Multi for DOGS contains more Moxedectin than the cat version. For example, the dog formula for a 9 lb dog would be 40 IMIDACLOPRID and 10 MOXIDECTIN where the cat formula for a 9 lb cat is 40 IMIDACLOPRID and 4 MOXIDECTIN. Moxidectin is responsible for handling heartworm and intestinal worms. The ~2.5x difference is what I find concerning enough to not recommend using the dog formula on cats.

      The down dosage for Advantage Multi for cat can be more weight specific by applying the math of 0.05ml/lb, so a 7 lb cat would get .35 ml rather than 4 ml. If you have a lot of cats, the difference eventually treats another whole cat. 🙂

      Hope this helps.

  16. Misti says:

    I believe this will help a lot of people that have multiple pets that can’t afford to keep them treated without some kind of a break. Doing it this way allows a person to give their pet a better quality of life. I’m grateful for this site and all the information. Thank you

  17. Dawn McGlohon says:

    Yes, I see Advantage and Revolution.. the med that I’ve purchased is Activyl. Thank you for your time if someone has used Activyl in dog packaging and dosed it down for cats. I was going on the info sent in response to “Tim” in July 2019.

  18. Dawn Mc says:

    Hi, I found your site and I really appreciate. Like a lot of people, I have found that Advantage no longer works down here, and Revolution is just too far off the price spectrum. I have had good success with Activyl but never thought to buy it for XL dogs and dose it down for cats. I found this information above but that is a really big range 0.128 – 0.85 mL/kg bodyweight ..? An 8lb cat could either get 0.5ml up to 3ml. That’s a huge difference. Am I doing something wrong? Thanks!

    • isak says:

      In the paragraph above the dosing chart there is a more precise measure. For example — above the chart for Revolution, it says: Dose is 0.025ml/pound. Multiply 0.025 times your pet’s weight for more precise dosage. For Advantage, it says: Dose is 0.05ml/pound. Multiply 0.05 times your pet’s weight for more precise dosage.

      You can use these more precise measures to zero in on how much to use for your companion.

  19. Evelyn says:

    Would the dosage be the same for K9 Advantix II and Advantix? My puppy is about 2.5 to 3 lbs

    • isak says:

      Yes, the difference between the two is the addition of Pyriproxyfen to Advantix II that affects mostly young insects and eggs.

  20. Helen says:

    Now there is Frontline ‘GOLD’ Does anyone know if the large dog dose for cats is the same as the Frontline ‘Plus’? Thank you.
    I also think this is a wonderfully helpful site and thank you for helping the lady with info for her ferals that needed to be spayed/neutered!

    • isak says:

      Thanks for the heads up. Frontline states that their Gold product is safe for cats, so I would imagine it can be dosed down. We’ll see if we can find a measure and add it to the page.

  21. Tara says:

    I have Advecta 3 for xlarge dogs. I can’t seem to find Advecta 3 dosages on any other sites. I have a 10lb dog.

    • isak says:

      I don’t have the specifics for Advecta. There may be an insert in the product that states more specifically how much to apply per pound, but in general, the dosage is:

      5-10 Lbs= 0.4 ml
      11-20 lbs= 1 ml
      21-55 lbs= 2.5 ml
      55 & up= 4.01 ml

      So in the case of your 10 lb dog, it looks like you would use 0.4 ml.

  22. Art says:


    I work in cat rescue and came here for the dosage for cats for Frontline (we normally use Advantage or Revolution).

    I noticed however that either your 0.0305 multiplier is wrong or your dosage for 1-9lbs. is incorrect.

    0.0305ml x 9 = 0.2745ml, which is significantly smaller than your listed 0.5ml.

    Rescue groups give 0.5ml for adults cats so your 0.5ml is correct.

    However the multiplier for 9lbs is 0.0555555556; 10 lbs. is 0.05

    9lbs. x ? = 0.5ml
    ? = 0.5 / 9
    ? = 0.0555555556

    For simplicity we can call it 0.05

    To meet your listed 0.5ml for a 9lb. cat, the correct multiplier is roughly 0.05 which changes the other doses:
    10lbs x 0.05ml = 0.5ml
    15lbs x 0.05ml = 0.75ml

    I noticed this because you listed 0.5ml for 1-9lbs, then 0.3 for 10lbs and 0.45ml for 15lbs.

    Being that 0.3 and 0.45 are both smaller than 0.5, using smaller dosages on a bigger cat didn’t make sense.

    Hope this helps and wasn’t confusing.


    • isak says:

      Thanks much for the input. I will check the numbers and make the adjustments as needed.

      Update 08/07/19: We had included the dosage from the package in the original post. I think that is where the confusion came in, so we have deleted that info and restructured the tables so they are hopefully easier to read. Please let us know if you note any problems/questions.

  23. Tim Waits says:

    Love the site and the calculations are spot on. However, do you have the calculations for converting Extra Large dog ACTIVYL for use on cats?

    • isak says:

      The recommended dose for cats is 25 – 166.6 mg indoxacarb/kg bodyweight, equivalent to 0.128 – 0.85 mL/kg bodyweight. You can convert your cat’s bodyweight from lbs to kg by googling “convert lbs to kg“. Here’s a chart showing the dosage breakdown for Activyl.

      As a caution, the manufacturer states: Do not use Activyl for dogs on cats, or allow your cat to lick or groom a dog treated with Activyl. This is likely a precaution so cats do not overdose on the product, so proceed with caution, especially if using this on multiple cats at one time.

  24. T Fagan says:

    I just wanted to say I refer to your website again and again. Thank you for all your information. That was really nice that you helped guide the lady with the feral cat issue in Texas.

  25. Heidi says:

    And 1st off: Thank you! Thank you!

    I apologize if I somehow missed it…I have a 10lb cat. But the only flee meds I have are for our large dog: 62lbs. We have Frontline and Advantage Multi…how can I convert one or the other to use on my cat? And by the way after long extensive is searching for a very long time this is by far the best website I have found

    • isak says:

      Thanks for the compliment!

      You will need a small oral syringe to do this. If you don’t have one, they can generally be purchased at a pharmacy or a feed store for a few cents.

      For Advantage Multi, multiply 0.045 times your cat’s weight for the dose. So .045 x 10 = .45ml.

      For Frontline, I have never found a measurement for plain Frontline for use in cats; just Frontline Plus which has different ingredients. So I cannot recommend that you use plain Frontline for your cat.

  26. Judi says:

    Thank you, so much for this!

    After reading your helpful information, in order to obtain the greatest savings, we would purchase the 6 pack Advantage Multi for the largest dogs. After doing the math for the exact dosage on our 12 pound dog, this 6 pack purchase would last us a little over 32 months.

    Can you advise if there is an expiration date on the individual 6 packs of Advantage Multi?

    • isak says:

      I believe the expiration date is on the box only. I have some Advantage here (not the Multi), but I do not see an expiration date on the individual tubes.

  27. VICTORIA BAKER says:

    Activyl (FLEA ONLY) formulation can definitely be used on cats, we have done so and our vet told us it was the same. Yes, from the usa, SierraPetMeds is a great resource and accept Paypal.

  28. Cynthia Kay Cramer says:

    I am on a fixed income and had a recent stroke. Recently blessed with about 25 feral cats many of them young and pregnant. No idea how they found me as I live about 10 miles out in the Texas country side but here we are. I have 6 cats and 3 dogs of my own and this information is so very helpful. The county I live in offers no affordable spay/neuter programs and I can no longer drive so I just keep feeding the masses and again, here we are. I am originally from Michigan and am missing the kill season on fleas so very much. Thanks again.

    • isak says:

      I’m not sure where you are located but there is an clinic in Brenham called Animal Friends of Washington County that works with a lot of the area rescue groups. Give them a call and explain your situation. Maybe they can hook you up with some rescue groups that could help you because those babies will just keep multiplying and you will get overwhelmed.

      Here’s their phone number: (979) 277-0400

  29. T.W says:

    Thank you for this post,
    As a multiple cat owner this is extremely important information to have,
    I have to say thought, that recently, it seams that the usual flea med I have been using (namely Advantage and Revolution) does not work in eliminating my cats flea problem 🙁
    I was wondering if you have any information about the Bravecto’s solution efficiency, can I dose it down (I think it has the same active ingredients in the same concentrations), and how much should I use on my cats.

    Thank you!

    • isak says:

      It seems to me that most flea meds last 3 weeks, not 4 at my house. I have not worked with Bravecto. It concerns me that something you apply topically (or even through an edible) would last for 12 weeks. What must those first weeks when the drug is most potent involve? So I generally steer clear of it. There is a product called Stronghold which is the same as Revolution, but cheaper.

      Sierra Pet Meds sells a supply kit for cats and dogs that is generally a bit cheaper, too.

  30. Kathleen King says:

    I use a company called Pets megastore. They are in located in Australia. Great prices and I get Revolution from them all the time. I worked for 7 years at a veterinary office. I learned a lot from the reps. that sold us our flea control. Learned how to break it down to save money. I have also been in rescue for years. I have learned different ways of saving money on meds and flea control. I use to do all the drug ordering for our vet. office. Pets mega sells Virbac tapeworm pills my vet used. They are in kilograms. 1-pill does a 22lb. dog or cat. I use 1/2 pill for an 11-pound cat, 1/4 pill for 5.5 lb. cat. You get the idea. Saves a lot of money. Please check their site. I live in Calif. and have used them for over 10-yrs. I have never had any problems and receive my order in 7-days. I hope this information helps.??

  31. Tanya says:

    hello Isak, Thank you for this valuable website.
    I’ve been told by a farmer that I can use the product Thiraflo active ingredient is Thiram. It is a fungicide that’s used to spray seeds. He said it’s the same as Fipronil, the active ingredient in flea treatments.
    Is any of the information he gave me correct. Have you heard of this Thiram chemical being used on animals.
    Is it safe to do so. Thanks so much for your help

    • isak says:

      Thiram is a fungicide; Fipronil is an insecticide. I don’t see that they are the same thing at all. I would not recommend Thiram.

  32. rose green says:

    great reference.
    my favorite flea killer is comfortis. no worries about seperating them or licking it off themselves or each other. cats may not be able to lick the back of their own head, but my cats help each other with the hard to lick areas.
    so i do the same thing with comfortis (for xl dogs) & a digital postal scale (it needs to weigh to hundredth, meaning it has to have 2 numbers after the decimal point). the dosage for dogs is .13 & cats is .22, but i dose mine at .1 for dog & .18 for cats. ive tried the higher dose, but it still doesnt last 4 weeks & causes lethargy & upset tummies. so i give the lower dose about every 3 weeks. i crush up the giant pill & dose all the ones who will let me weigh em by their exact weight, like a 10 lb cat get 0.18 on scale. 5lb gets 0.09
    7lb comes out to .126 on calculator so i round it to 0.13
    i guess for the ones who wont let me pick em up & i try to guess on the high side. they’re still getting less than if i bought expensive individual doses for each cat, where they have u give a 5 lb cat & 10 lb cat the same dose!
    i make em wait a few hours past mealtime so i know theyre really hungry. i massage the appropriate amount of powder into the pillpocket (so there aren’t any pieces to spit out) & i top with the littlest bit of wet food, like 1/4 teaspoon, so they eat it all in one bite & no one accidentally eats extra doses.
    after everyones dosed they get canned food (with a lil olive oil added) as much as they want cause it works better with a belly full of a fatty meal. i keep an eye on em for an hour cause if they barf they need another dose or a topical to kill the fleas.
    i order my comfortis xl online, from a country where an rx isn’t needed

  33. Susan says:

    Thank you for this site!

  34. Dawn says:

    Thank you for creating this site. Im on a fixed income and have used a single frontline for large dogs on my 2 medium sized dogs and my 8 cats each month of flea season for several years. I measure carefully and my very effective flea treatment cost me under 20 dollars a month. This is a great way to get this info out there so multi pet families with a low income can keep their fur babies comfortable throughout flea season.

  35. Iris Wilner says:

    What is the best flea prevention that last the longest. Need safe for kittens.
    And do Fleas have to bite to work.

    • isak says:

      The “best” is probably a personal choice. My personal choice is Revolution. It is effective in keeping cats safe from adult fleas, flea eggs, flea larvae, as well as heartworm, intestinal worms and other nasties. Revolution is approved for use with kittens and puppies as young as 6 weeks old, as well as pregnant and lactating females.

      That said, it seems that most of the flea meds I have tried start to wear off after three weeks, not the four they promise, but I also dose based on weight and not the general weight class of the med.

      Just be sure that when using any of these products on cats or kittens that you apply it as directed so they cannot lick it or otherwise get it in their mouth (like paw the area where the meds are and lick their paws). You want to apply it onto the skin just in front of your cat’s shoulder blades.

  36. Bettina says:

    I was told by a vet to always stay away (far away) of anything ending in ‘thrin, she called them “the thrins”. This warning to stay away is for cats, and as you said “permeTHRIN” is a baddy. Thanks to you and all the compassionate vets out there who know how ridiculously and unnecessarily expensive this stuff is,and do what they can to help people make safe choices for their furry friends! Hate those bloodsuckers.

  37. Michelle says:

    Hi !i wanted to ask Debra if she did in fact use the termite “ medication?” And if everything worked out fine as I somehow adopted three stray females and before I could fix (of course this is certainly fun for my daughter and I?) all three have had Kittens!! ? so we currently have seventeen kitties! Of course only two litters are over the dosing ages but I would like to do it before I give them away. So was just wanting to know.
    In addition, now do you think between my nine year old daughter and I loving all these – that all aeventeen will be leaving?? Ha! ? I don’t believe I will need to answer that! (Omg I picked more than her!) lol Okay thanks! Bye bye! 🙂

  38. Debra says:

    So most Fipronil products have methoprene ….. if you find it can you use straight Fipronil 9.1% at these same dosages? Most termite control insecticide is Fipronil 9.1% like Taurus SC in its concentrated form…. I bought a 20 oz bottle to treat the yard when I realized this is the SAME minus the methoprene. For anyone with 20+ cats this can be a $$ saver. 20 oz was $43. Wat would be your take on it?

    • isak says:

      I don’t have a good answer for you. One concern would be the effects of applying this product directly to the skin as these are serious chemicals. I would do more research before giving this a try as complications may not appear immediately after dosing. Personally, I buy large dose dog flea meds and dose them down.

      Here is some scary info about flea meds in general. Though it is several years old, I think it may still be relevant today.

  39. Ann says:

    I’m sorry may be a little confused. I have just ordered Revolution for extra large dog 3 pack. I want to break it up in doses for my 22 pound dog. What is the dose I would give her?? Thanks a lot

    • isak says:

      It can be confusing, but the formula is pretty simple. The potency in the dog versions is 120 mg/tube in all but the smallest (puppy) tubes. If they didn’t reduce the potency in the smallest version, the product would be all tube and very little flea solution. You say you bought the extra large dog pack and your dog is 22 lbs. so what you want to do is multiply your dog’s weight by 0.025 to get your dose.

      22 x .025 = 0.55 ml

      If you go a bit above this amount, it will not hurt.

      To verify this amount, look at the box for a 10.2-20 lb dog. The amount in each tube is 0.50 ml. Your dog is slightly heavier so your dose is slightly higher: 0.55 ml.

      Hope that helps.

  40. Johanna Baumgartner says:

    Wow – This is such a work of love. Thank you so much. I have yet to totally figure everything out, but the concept of reducing the amount of flea medication is really important to me given the reactions and deaths that occur from some of these mediations. Thank you again.

  41. Sandy B says:

    What are your concerns and thoughts regarding Fluralaner (Bravecto) for dogs?

    • isak says:

      I don’t have any experience with Bravecto. Though it is touted as a 12-week solution for fleas and ticks, it seems that for the Lone Star tick, they recommend redosing every 8 weeks. You can read this endorsement from a vet in Canada. A “Freedom of Information Summary” [PDF] dated 15 May 2014 is available on the Food and Drug Administration’s (FDA) web site. It’s an interesting read. From it, there is this:

      There were no clinically-relevant, treatment-related effects on physical examinations, body weights, food consumption, clinical pathology (hematology, clinical chemistries, coagulation profiles and urinalysis), gross pathology, histopathology, or organ weights. Diarrhea, mucoid and bloody feces were the most common observations in this study, occurring at a similar incidence in the treated and control groups. Five of the twelve treated dogs that experienced one or more of these signs did so within 6 hours of the first dosing. One dog in the 3X group was observed to be dull, inappetent, with evidence of bloody diarrhea, vomiting and weight loss beginning five days following the first dose. One dog in the 1X group vomited food four hours following the first dose.

      So just be aware of the side effects you might encounter. And if you try it, let us know what you think. I’d love to share your experience with our readers.

  42. Adele says:

    I wanted to say thank you so much for all the information that is provided here. It has been such a help in figuring out dosage amounts of flea treatments for our animals. Like many people who visit this site, we take in strays, we try to get them spayed and nuetured but cant seem to ever get them all fixed in time. Our “colony” is at 60+ cats and kittens right now, not to mention the 6 dogs we have as well. The flea meds we were using stopped working and have recently switch brands to advantage 2 for the cats and a generic brand called pet defender+ for the dogs. However we ran out of the advantage before all the cats were dropped. There are about 12 who have not been treated. Is it ok to drop the remaining cats with the drops that are for the dogs? Any help would be greatly appreciated. We are beyond overwhelmed.

    • isak says:

      Wow, 60+. You have me beat.

      I am not familiar with Pet Defender+, but in general, if they make a cat version, compare the ingredients to the dog version. If they are the same, you should be okay. If the product contains permethrin, DO NOT use it on the cats. While dogs can metabolize permethrin effectively, resulting in a safe product for them, cats cannot metabolize this ingredient and will suffer from toxic effects if exposed.

  43. Carrie says:

    I have a question. Sorry if it’s listed somewhere. I have multi-dosed our pets before. I use Frontline Plus. Anyway, I think I bought the extra large dog size and dosed it out from there. I can’t remember since it’s been awhile since I needed to buy new. Do it need to get the extra large for the doses to be correct? Thank you.

    • isak says:

      The dosage is based on the weight of your pets. The extra large will generally cost you less per dose than the smaller sizes and you will get more doses out of the tube. However, if you open a tube and do not use it all, you need to close it tightly and keep it out of the light.

  44. Sharon George says:

    Bless you for all you do. REALLY appreciate this website. I’ve had to switch to Activyl as the Advantages 1 & 2 don’t work anymore, and I can’t buy Revolution w/Paypal in America, not for a decent price, anyway.

    Like everyone else, I rid many rescues and several colonies of fleas, and doing 20+ cats on a fixed income…it has to be as cheap as possible.

    Have you tried Activyl – fleas ONLY for X-large dogs…on cats? I’d love to get a lowdown on the dosages. Thank you!

    Bless you for all you do. We’ve been rescuing cats off our streets for 15 years. I’m a bottle mom. Love it!

    • isak says:

      Thank you for your kind words. And bless you for all you do. I live in the country and somehow, stray cats seem to migrate to my yard despite having dogs (who love cats because they have always lived with cats), so I understand what you are saying. Advantage seems to work for me, but only for 3 weeks max. I’ve read where other people have reported that, too.

      I don’t know much about Activyl, but if the quantity of the active ingredient is the same in both products (for example: 19.53% Indoxacarb in both products), then there is a good chance that the non-tick version can be dosed down for cats. That’s generally the qualifier — same product, same ingredients, different packaging. So based on what the dosages are showing for the different products, you can determine how to dose your cats. Maybe the dosing amount will follow something similar to others we are showing on this post and that will help you micro-tune your dosages.

      Have you tried Sierra Pet Meds for your flea medications? I think they might take PayPal. They generally have good prices and they have a rewards program. I have used them often.

      Let me know what you do and how it works. You aren’t by chance in or near Raleigh, NC, are you? If so, there is a woman with some health/mobility issues who is looking for help with her colony. Any suggestions would be appreciated.

  45. Cris Lenard says:

    I am so very grateful to you for providing this information! We have 5 cats and 2 dogs (all rescues), and I have often been riddled with guilt when funds have been too tight for flea meds (which seems to be too often). All 9 of us (my hubby and self included) THANK YOU, THANK YOU, THANK YOU!!!!!!!!!

  46. Andrea says:

    Thanks so much…I am broke, on a fixed income but I am going to try and donate thru PayPal link provided.

  47. laura says:

    Thanks for posting this! I have been using half-doses of the anti-flea products for years and I have never had a single problem. Here in Michigan, I completely stop dosing around November – March (in my dog-loving neighborhood, I recently discovered that most dog parents are doing the same thing) . The doses given full strength as indicated on the package inserts, when I have tried them, have always made my pets ill for a couple of days after I apply the med. The half-dose works just fine with far less side effects. I wonder if, by poisoning the fleas, we aren’t poisoning the animal at the same time.

    I do get all of the recommended vaccines, though.

  48. Jacqui Rengstorf says:

    Thank you so much for listing all of the dosages for those different products. I’ve been doing the same thing for over 17 years now. I was taught by a wonderful – and spunky!! – little rescue lady ? But I still always like to doublecheck the dosage sizes when I switch products – I don’t want to use too much. The dosages for Advantage and Advantage II are the same, right? I am inquiring for my darling 2 yr old border collie / fox terrier mix named Dodger who weighs 49 pounds, which puts him in the large dog category. Thank You!!

    P. S. I should have mentioned that I have both products on hand. Dodger seems to have a mild allergy to fleas so I wanted to use a Advantage II on him based on what you wrote. While I mentioned him, I do have cats as well so it would be handy to confirm that their dosages with the Advantage II is also the same as the regular Advantage ?

    • isak says:

      Yes, the dosage is the same for Advantage and Advantage II. The difference between the products is this: Advantage required adult fleas to ingest the medication, at which point they would be impacted by the insect-specific neurotoxins and die. Advantage II kills fleas on contact, with the addition of three new chemicals to its formula, that makes your dog or cat’s skin an entirely inhospitable environment for pests. Eggs are killed before they hatch. Adult fleas are killed and will fall off, or will be washed off in your dog’s next bath.

      However be sure you do not use K9 Advantix or Advantix on your cats. It’s a dogs only formula.

  49. Mireille Brosset says:

    Check Dr. Foster & Smith for cheaper multi. They have a sale on this product now.

  50. Kim says:

    Thank you you so much for this info. We live on a farm and have 6 dogs ranging in size from 6 to 95 pounds. I had already.been splitting dosage vials between 2 dogs when appropriate. So recently I thought, why not try to let the product and our money go further by finding out the dose per pound that would be effective. This article was amazing in giving info on all of these products. It was also helpful to find out the important storage info. I wish that more people could be made aware of this info. It seems like it will be good for our pets to have only the necessary amount of insecticide as well. Thanks again for this very informative article.

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