Revolution Plus For Cats: Overview, Dosage & Side Effects

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Revolution Plus for cats is a brand of topical, “spot-on” medication that prevents fleas, ticks, intestinal parasites, and heartworms. Revolution Plus contains the main ingredients selamectin and sarolaner. It is a newer incarnation of its older predecessor, Revolution for cats.

Revolution Plus For Cats Overview

Medication Type:
Avermectin topical antiparasiticide
Topical liquid solution
Prescription Required?:
FDA Approved?:
Life Stage:
Cat and kittens 8 weeks of age and older and weighing at least 2.8 pounds.
Brand Names:
Common Names:
Selamectin, sarolaner
Available Dosages:
Topical solution: up to 5 pounds (mauve packaging, 15 mg/tube), 5.1 to 15 pounds (blue packaging, 45 mg/tube), 15.1 22 pounds (taupe packaging, 60 mg/tube)
Expiration Range:
Products should be used before the expiration on the package. Packages should be stored below 86 degrees F (30 degrees C).

In this article, you’ll learn about Revolution Plus for cats, the ingredients it contains, the types of pests it targets and parasite protection it provides, possible side effects to consider, and some frequently asked questions.

For more information about the original Revolution product and more insight on how it compares to Revolution Plus, see Revolution for Cats.

About Revolution Plus For Cats

itchy cat

The main ingredient in Revolution products is selamectin. Selamectin is a topical avermectin antiparasiticide. Selamectin works by enhancing release of a neurotransmitter called GABA. In certain parasitic worms like roundworms and in arthropods like fleas, GABA inhibits nerve conduction. By enhancing GABA release, selamectin essentially causes paralysis and death of the parasites it targets.

Revolution Plus also includes sarolaner, which is an isoxazoline class acaricide/insecticide that inhibits GABA, leading to neuromuscular overstimulation and death of the parasites it targets. Sarolaner broadens Revolution Plus’ spectrum to include three types of ticks: the American dog tick, black-legged/deer tick, and the Gulf Coast tick.

Revolution Plus spot-on product is a monthly topical solution applied to a small target area or “spot” of the skin, usually in front of the shoulders at the back of the neck.

To get a lethal dose of selamectin or sarolaner, the parasites don’t have to bite a treated cat; simply coming in contact with the skin is enough. However, it’s important to note that Revolution products for cats do not provide true repellency that would prevent fleas or ticks from coming in contact with a pet.

What Does Revolution Plus Do For Cats?

Revolution Plus has action against many common parasites. Revolution Plus does the following:

  • Kills adult fleas
  • Prevents flea eggs from hatching
  • Treats and controls two intestinal parasites (roundworms and hookworms)
  • Treats and controls ear mite infestations
  • Prevents infection with mosquito-borne heartworms
  • Kills ticks

According to the manufacturer, when newly applied, Revolution Plus can start killing fleas within 12 hours, with a majority killed within 24 hours. When already applied prior to flea exposure, Revolution can start killing fleas within six hours, with a majority killed at 12 hours.

In a couple of studies, Revolution Plus was found to kill fleas before they could lay eggs, preventing further infestations from starting if the product is used consistently.

The manufacturer states that in lab studies, Revolution Plus started to kill the black-legged/deer tick within 24 hours with a little over 90% effectiveness for one month. It also demonstrated over 90% effectiveness against the Gulf Coast tick and the American dog tick.

As a heartworm preventative, Revolution Plus was found to be 100% effective in preventing the development of heartworms in cats when those cats were exposed to larvae about 30 days prior.

Revolution products can also help to control ear mites, which are pesky, itchy pests that occupy the ear canals, usually of young cats or kittens. Revolution Plus was over 99% effective at eliminating this parasite.

Lastly, Revolution plus was found to be nearly 100% effective against intestinal hookworms and roundworms in cats over a 60-day period of study.

Side Effects Of Revolution Plus For Cats

Revolution Plus kills three common tick species (American dog tick, black-legged/deer tick, and Gulf Coast tick).

When used properly, side effects of Revolution products for cats are uncommon. Revolution Plus is labeled for cats 8 weeks and older. Revolution Plus is also restricted to cats weighing at least 2.8 pounds. Topical products like Revolution should never be ingested.

In clinical trials for Revolution Plus, a little less than 5% of cats showed signs of looking excessively tired, less than 4% showed signs of skin irritation, and about 3% showed signs of a decreased appetite. No hair loss was documented with Revolution Plus, which had previously been documented with regular Revolution.

At least some of the digestive upset and signs of excessive drooling that may be seen with use of topical products like Revolution Plus may have occurred secondary to cats licking the product off of themselves after application.

Products like Revolution Plus are very bitter tasting, so if a kitty were to lick a recently applied product off either themselves or a housemate, the bitter taste alone can lead to excessive drooling, agitation, and sometimes even vomiting.

According to DVM360, this effect is typically not a true toxicity, but a sometimes dramatic reaction to the bitter taste. Providing milk or liquid from a can of tuna can help resolve the signs in short order.

To avoid this from happening, it is important to apply any topical flea/tick product to the skin in front of the shoulder blades at the back of the neck, a location even the most flexible cat cannot reach to lick. In multiple cat households where lots of co-grooming occurs, separating housemate kitties for up to 24 hours after application to allow the product to fully dry may be advisable.

Although Revolution products for dogs and cats contain the same active ingredients, the manufacturer does not advise using a dog product on a cat, even if they are similar in weight. Sometimes, there are differences in the inactive ingredients between dog and cat products that would make them inappropriate to consider interchangeable.

Using Caution With Other Flea/Tick Products

While Revolution Plus for cats has been established as a safe product, the active ingredients may be found in other products in combination with other ingredients that are not safe for cats. This is especially the case with dog products like K9 Advtantix II, which contains permethrin, a substance that is extremely toxic to cats.

Fortunately, these products are now required to include a warning against use in cats. But just to be safe, when selecting a flea/tick product for your kitty, always make sure the product includes a picture of a cat and indicates the product is specifically for cats.

It is also always advisable if you have a pup and kitty who like to hang out together or groom each other to separate them for 24 hours after applying a topical product to your dog, especially if the product contains permethrin.

If you have any concerns for potential toxicity, even if you think your kitty might have just licked some Revolution Plus off her fur and is having a bitter taste reaction, it is always best to contact your veterinarian, the ASPCA Animal Poison Control Center (1-888-426-4435), or Pet Poison Helpline (1-855-764-7661) immediately for further advice.

And lastly, topical products like Revolution Plus have been known to cause skin and eye irritation in people. It is best to avoid contact with the solution during application and to wash your hands after.

Unlike regular Revolution, Revolution Plus contains the added ingredient sarolaner, which adds to its spectrum against ticks. Isoxazolines like sarolaner have been associated with adverse neurologic signs in some pets, including seizures and tremors. Use of Revolution Plus should be considered carefully in cats with any history of neurologic illness.

Revolution Plus For Cats Dosage

Before purchasing Revolution Plus, find out how much your cat weighs so you can buy the correct dosage.

Revolution Plus is typically applied every 30 days for the best protection. Revolution Plus is approved for use in cats and kittens 8 weeks of age and older.

Revolution Plus comes in three sizes as a topical solution for cats weighing 2.8 to 5.5 pounds, 5.5 to 11.1 pounds, and 11.1 to 22 pounds. For cats that exceed 22 pounds, the manufacturer recommends using a second dose in combination as appropriate (i.e., a cat weighing between 23 to 27 pounds would get one 11.1 to 22 pound dose combined with one 2.8 to 5.5 pound dose).

Safe use of Revolution Plus or any topical product for your kitty means always following all instructions on the packaging. Revolution Plus vials have a cap that first needs to be pushed down into the vial to puncture it.

The cap can then be removed, and the entire contents of the vial applied by parting the fur and applying to the skin along the back of the neck in front of the shoulders where a kitty cannot reach to lick it off of himself.

While Revolution Plus topical solution is considered to be waterproof within two hours of application, the manufacturer still recommends waiting 24 hours to bathe your kitty after application. Bathing shortly before application may also reduce its effectiveness.

If for some reason you are unsure if the product was administered correctly or whether all of it was applied, it is usually safest to not apply an additional dose.

If you have any questions about application or safety for Revolution Plus or any topical product, make sure to get in touch with your veterinarian.


Revolution Plus is the newest incarnation of Revolution, a product that has been used for cats for many years and is generally a safe and effective product when used properly. Because it is a heartworm preventative, you must obtain a prescription from your veterinarian before purchasing Revolution Plus.

Frequently Asked Questions

What does Revolution plus do for cats?

Revolution Plus has many actions against parasites in cats. It is effective at killing fleas and preventing further flea infestations, it kills and prevents three different kinds of ticks, prevents mosquito-borne heartworm disease, treats and controls the intestinal parasites hookworms and roundworms, and treats and controls ear mites. 

What is the difference between Revolution and Revolution Plus for cats?

The main difference is Revolution Plus contains the isoxazoline drug sarolaner in addtion to selamectin. Sarolaner allows for Revolution Plus to have a better spectrum of activity against ticks. 

While regular Revolution only provides some protection against the American dog tick and is not labeled for this in cats, Revolution Plus has labeled action against not just the American dog tick, but also the black-legged tick that carries Lyme disease, and the Gulf Coast tick. All three ticks are extremely common in the United States. 

Do you need a prescription for Revolution Plus for cats?

Yes. Because Revolution Plus is a heartworm preventative, it does require a prescription as all heartworm preventatives do. 

Even if ordered online, a prescription request will still need to be sent to your veterinarian for approval. The main reason for this is that some pets can be at a higher risk of a reaction for some products if the product is given or applied while the pet has an active heartworm infection. 

While cats are not as routinely tested for heartworm as dogs are, owing to the fact that only about 50% of cats truly infected with heartworm will show up positive for the disease on a test, it’s still important for a veterinarian to verify that a kitty is not showing signs of illness prior to starting.

How long does it take for Revolution Plus to work on cats?

According to the manufacturer, Revolution Plus starts working to kill fleas within 12 hours, with a majority killed within 24 hours. When already applied prior to flea exposure, Revolution can start killing fleas within six hours, with a majority killed at 12 hours.

Over 90% of the three ticks it targets were effectively killed on cats over a 60-day period of study, with the black-legged tick being killed within 24 hours. Ear mites, roundworms, and hookworms were all effectively killed by the product.

While Revolution has slower kill times for fleas and ticks compared to other topical products like Frontline Plus and Advantage II, the ingredients in Revolution Plus make it one of the best all-around products for cats, with the best broad spectrum of coverage targeting fleas, ticks, heartworm, and intestinal parasites.

If you feel you’re not seeing good efficacy from the product, especially when it comes to flea infestations, please consider the following.

The question of flea resistance to products like Revolution Plus and the idea that they don’t work comes up often. The 2017 article “Perception vs. Reality: Insecticide Resistance in Fleas” from DVM360 that refers to an article published in American Veterinarian that same year addresses this topic.

An entomology (“bug science”) professor from the University of California heavily investigated this question and concluded that while resistance has been seen to some flea treatment or prevention products, true chemical resistance in fleas with fipronil, imidacloprid, and some other newer products on the market has not yet been demonstrated.

In many cases, when a pup or kitty parent is still seeing live fleas on their pet after a product has been applied, this issue can most often be traced back to incorrect use or application of the product, as well as poor expectations.

Following are some common errors or misperceptions.

  • Incorrect application (i.e., applied to the fur not the skin, failing to apply the whole volume of product, failure to properly puncture or open a vial prior to application)
  • Failure to apply to all pets in the household. If one pet brings fleas indoors, they can jump onto all pets in the home. If all pets are not treated at the same time, flea infestations can persist.
  • Bathing. Baths are a common go-to, especially when live fleas are seen. However, while waterproof, Revolution products need 24 hours to spread throughout the oils on the skin. Bathing shortly before or after application removes oils from the skin as well as possibly the product itself.
  • Not treating long enough.  It can sometimes take as long as three months to clear out a flea infestation. So while most veterinarians advise year-round protection against fleas and ticks, a product like Revolution Plus should be used every month for at least three months during an active infestation. Flea eggs not cleared from the home environment are likely to continue hatching every couple of weeks, meaning a kitty that received only one monthly dose of Revolution Plus can get infested again a few weeks later if the dose is not repeated the next month.
  • Not treating year-round. Fleas have been known to over-winter indoors. Treating pets for only certain months of the year can leave open gaps in prevention for infestations to occur.
  • Failing to treat the environment. Because one flea can lay up to 50 eggs in just one day, the amount of eggs in a home environment with fleas can be staggering. If the environment is not treated effectively, continually hatching fleas may continue to be found on a treated pet.
  • Perceiving products as repellents. Always remember that most topical products like Revolution Plus do not have repellency action, meaning that fleas and ticks must come in contact with the skin to be killed. Heavily-infested outdoor areas as well as poorly-treated indoor infestations can be sources for large numbers of adult fleas to “suddenly” appear on a treated pet.

If you still feel there’s a true product IssueIf you feel you have applied a product properly and are addressing a flea infestation according to your vet’s instructions and still feel that a product is not working well, make sure to bring those concerns to your vet or contact the manufacturer of the product.

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About Dr. Chris Vanderhoof, DVM, MPH

Dr. Chris Vanderhoof is a 2013 graduate of the Virginia-Maryland College of Veterinary Medicine (VMCVM) at Virginia Tech, where he also earned a Masters in Public Health. He completed a rotating internship with Red Bank Veterinary Hospital in New Jersey and now works as a general practitioner in the Washington D.C. area. Dr. Vanderhoof is also a copywriter specializing in the animal health field and founder of Paramount Animal Health Writing Solutions, which can be found at Dr. Vanderhoof lives in the Northern Virginia area with his family, including 3 cats.

19 thoughts on “Revolution Plus For Cats: Overview, Dosage & Side Effects

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Phylis, I’m sorry to hear you’re seeing these signs in your kitty. Skin irritation is uncommonly reported with Revolution Plus, though hair loss was not, at least not in clinical trials. If this was a recent application, it can help to use warm water and dish soap (like Dawn) to gently clean the area and remove any residue on the skin. Make sure to touch base with your veterinarian to see if any other recommendations might be made based on being more familiar with your cat’s health history. This would be worth reporting to Zoetis, the manufacturer, as perhaps incidents of hair loss have been reported and they could provide better information on any additional steps to take and what to expect. Needless to say, if your kitty had a bad skin reaction like this and is very sensitive to it, Revolution Plus is likely not an appropriate product to continue using for him.

  1. Jackie Ellis

    I have a 5 cat household. Their weight varies. I have one cat that weighs two pounds 13 pounds. Will the 5.6 lbs.- 11lbs. still work on this cat? I cannot buy single tubes for his weight. I am on a limited retirement budget. How to I fix this issue?

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Jackie,
      Thanks for your question, but I unfortunately do not have a terrific answer for you. All flea/tick preventatives should be thought of as medication and their dosage ranges need to be followed closely. Using a range that exceeds a pet’s weight carries a greater risk of side effects. These products typically have a high safety margin, but the principle is still valid and they need to be used according to label. Using a dose range that is too low carries the risk of not being effective. If the remaining cats are in the proper range for what you have and have the product on, the risk of fleas would at least be lower if one kitty does not. You cannot split the vials or use a little less for a small cat or add a little more for a larger cat, as you then really have no idea what dose the cat is getting and these products were not meant to be used in that way, invalidating any guarantee the product has. I wish I could get you a better anwswer, but here’s really not much more you can do other than to have the correct dose ranges.

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Cynthia,

      Consider holding off on another dose and first confirm what types of intestinal worms you’re seeing, as Revolution Plus can only kill certain ones, roundworms and hookworms. Of those two, only roundworms are visible, resembling long spaghetti-like strands.

      However, one of the most common types of worms we see in cats are tapeworms (which can be seen a couple weeks after an exposure to fleas), which resemble small rice-like segments. Revolution Plus cannot kill tapeworms. If you’re seeing worms resembling pieces of rice, using another dose of Revolution Plus will not help.

      It can help to send a photo of what you’re seeing to your vet to confirm worms are present and get a recommendation on the right type of dewormer. A product containing praziquantel is typically used for tapeworms.

      Other things to consider for persistent worms in the stool include sending a stool sample out through your vet.

      Hope that helps.

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Christine,

      Yes, if your cat is 10lb, you can use two of the 2.8-5.5 lb doses of Revolution Plus. The manufacturer does indicate that combination doses are acceptable. In terms of actual drug doses, each of the 2.8-5.5 lb doses is 15mg of selamectin and 2.5 mg sarolaner. The 5.6-11 lb dose contains 30 mg of selamectin and 5.0 mg of sarolaner. So in using two of the 2.8-5.5 lb doses, you are still giving the exact equivalent doses of the two drugs as you would be with a single dose of the 5.6-11 lb dose. Hope that helps.

  2. Teressa kooistra

    I took in a stray cat and have used revolution plus for the past four months. The last three week she has had two seizures
    Despite many tests and. Xrays my vet can find nothing wrong. Is it possible revolution plus could be the cause

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Teressa,

      Thanks for sharing and I’m sorry to hear that you’re having these issues with your kitty.

      It is possible Revolution Plus could be related, but not certain. It contains two drugs. One is fluralaner, which is in the isoxazoline class, which provides most of the tick control. Isoxazolines have been associated with seizures in pets, though in my own experience, very uncommonly. Any product containing an isoxazoline carries this warning, but I don’t think it’s known how often this occurs.

      The second drug is selamectin, providing your flea and heartworm protection. Within the last year, researchers at WSU have identified that cats can have the MDR1 genetic mutation (which has been known about in dogs for about 20 years) that renders some cats sensitive to drugs including selamectin with seizures as a possible sign. However, this reportedly affects only 4% of cats, so is very rare.

      There can be many causes for seizures. In a stray cat, the risks can certainly be higher for infectious viral and parasitic causes, as well as previous trauma. I always worry about strays because we don’t know what they’ve had exposure to in their past life.

      If you’ve done general labwork and it looked normal, it does rule out several potential causes of seizures, but it’s not uncommon to see labwork look normal and be no closer to the underlying cause. An MRI can be an important part of working up a seizure disorder to look for structural abnormalities in the brain, but they tend to be expensive, so not often pursued.

      Whether the Revolution Plus is related or not, many vets will prudently advise to discontinue the product if a pet develops a seizure disorder, since the risk of a pet having seizures who is prone to them will be higher with an isoxazoline drug.

      If the Revolution Plus was related, you would expect the seizures to stop once the product is discontinued and out of a kitty’s system for 30 days. If the seizures persist long after Revolution Plus has been discontinued, then it certainly is more likely another cause is present. Best of luck.

    2. Jean Chapin

      Yes! See my comment below. I’ll never use it on my cats again. If it can kill just about any parasites on our cats for 3 months, what’s it doing to our cats?! I think I’ll stay with the tried and true.

  3. Jean Chapin

    I have 3 cats, all siblings, 2 had seizures 8 months ago, shortly after applying Revolution plus. After an extensive work up for each cat, and Mucho Dinero, my vet told me there was nothing wrong with my cats, and it was highly unlikely that the flea drops caused the seizures, and to keep an eye on them. I had the product in the house, but I chose not to use the revolution plus on my cats again because I suspected it caused the seizures. This week my vet told me it was safe and it was best to use the flea medicine because the fleas “are out there” this time of year. (My cats don’t have fleas btw). Against my better judgement I applied the Revolution + to all three cats, and today one of my cats had a seizure. Just putting it out there. Wish I would have listen to my instincts. Kitties are doing fine. They were not grand mal, but seemed focal. The cats were unable to focus, or walk for a few moments, then just sort of came out of it. And napped. If you see this type of activity in your cat after applying Revolution plus, I’d suggest not to use it. I am heartbroken that I put my cats through this.

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Jean,

      I’m sorry to hear that your kitties had these events occur. Seizures are not a common side effect of Revolution Plus, but they have been reported in some field studies.

      We know that dogs with a mutation called the MDR1 mutation can have seizures and other neurologic effects from ivermectin, selamectin, and similar drugs in that class. Collies and collie-like herding breeds are often identified as carriers of this gene mutation.

      Research on this gene mutation in cats is much newer, but it is known that cats can also carry the MDR1 mutation. However, unlike in dogs where herding breeds like Collies are more predisposed, there is no specific association with any particular breeds in cats, making it almost impossible to predict what cats may carry it.

      In February of 2022, the same researchers at Washington State University who discovered the MDR1 gene mutation in dogs and developed the test to detect it, also released a test for cats. Here is a link for a press release article with more information (including a list of drugs these cats can be sensitive to) and a link to the WSU website for MDR1 testing.

      If your cats are genetically related and you’ve seen recurrent seizure events after using selamectin, having your cats tested for the MDR1 gene mutation would be a good consideration. There are some other drugs used in veterinary medicine that these cats cannot metabolize well. Knowing this ahead of time can help prevent future adverse effects.

  4. Jean Chapin

    Thanks, that’s really good information. Just curious, why my vet didn’t know about this. She seems up to date. I’ll share this with her. Also where does one get a list of those medicines that can cause adverse reactions in cats with MDR1 gene mutations?

  5. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

    We’ve known about the MDR1 gene mutation in dogs for a long time and because it is classically associated with herding breeds, it’s been more straightforward for vets to discuss when we encounter those breeds. The MDR1 mutation in cats is very new. I’ve only become familiar with these findings within the last few months myself. Because there is no breed association in cats and according to WSU it only affect 4% of cats making it rare, it’s not a common discussion topic with cat owners. If you click on the press release article link, there is a list of medications pets carrying the mutation can be sensitive to. I can’t say of course that your cats have this gene mutation, but I would say with the circumstances you shared, it’s suspicious and worth testing them for it.


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