The Best Flea Treatment for Cats
Wipe out an infestation fast
The best flea treatment for cats should kill the fleas in your cat’s fur without causing harmful side effects. To help us uncover what products were safe and effective, we consulted with pet and insect experts, researched active ingredients, and tested the finalists ourselves. In the end, the right choice for you is a matter of your cat’s needs and personal convenience.
Frontline Plus for Cats kills all states of fleas, plus ticks and chewing lice. Its long, sturdy applicator makes it easy to apply directly to the base of your cat's neck.
Sentry Fiproguard Plus for Cats uses the same active ingredients for half the price, but the applicator is messier — not ideal when handling insecticides.
The Best Flea Treatment for Cats
Our favorite spot-ons are Frontline Plus for Cats and Sentry Fiproguard Plus. Both products use the same insecticide/insect growth regulator combination to kill all stages of fleas, ticks, and chewing lice. Like all spot-on treatments, the medicine is applied to a small area at the base of your cat’s neck, so they can’t lick it off. Because they’re spot-ons, you will have to keep your cat away from children and other pets for 24 hours until the product dries, but they start killing fleas in 12.
Sentry is the cheaper of the two, but we preferred Frontline’s clear, snap-off applicator. When we opened Sentry’s applicator, some of the medication leaked out — we had to take extra caution to make sure it didn’t leave a residue on our hands and scissors.
If you cat needs relief from fleas as quickly as possible, we recommend the oral tablet Sentry Capguard. All three of the oral flea medications we tested — Sentry, PetArmor, and Capstar — were identical products, but Sentry was the cheapest, with PetArmor coming in a close second.
They all start working in 30 minutes and kill 90 percent of fleas within six hours. The downside of oral flea medication is that they only treat existing fleas — they don’t prevent fleas or treat other insects. But because the medication comes in a tablet, you don’t have to worry about coming into contact with the product.
How We Found the Best Cat Flea Treatment
We compiled a list of every over-the-counter cat flea medication we could find on 1800PetMeds, Petco, PetSmart, Amazon, and manufacturer websites. We ended up with 75. With so many options to choose from, we focused our attention to 34 tablets, spot-ons, and collars (We figured most cats wouldn’t tolerate a flea shampoo bath or all-over spray.) From there, we dug into the research and talked to veterinary and insect experts to determine which medications could wipe out a flea problem while remaining safe for you and your cat.
First we learned not all flea medicines work the same way.
There are many different ingredients used in flea medicine, but they all fall into three major categories:
- Insecticides kill existing fleas by attacking their nervous systems. Imidacloprid, nitenpyram, dinotefuran, and fipronil are the most common. All of the flea treatments on our list use an insecticide.
- Insect growth regulators (IGRs) target the hormones of fleas and prevent them from developing and laying eggs, stopping future infestations. The most common IGRs include (s)-methoprene and pyriproxyfen. These ingredients are found in some topical, collar, and shampoo products from Frontline, PetArmor, and Sentry, among others.
- Insecticide synergists help insecticides work faster. Common insecticide synergists are piperonyl butoxide and n-octyl bicycloheptene dicarboximide. These ingredients are found in some shampoos and powders.
Avoiding Chemicals While our experts didn’t recommend natural treatments, there are still chemical-free ways to control fleas. Dr. Williams suggests regular baths and vacuuming your floors while treating your cat for fleas.
We also found a handful of garlic- or essential oil-based products marketed as “natural,” but none of the vets we spoke to could verify that these products are effective as insecticides. Dr. Ralph Williams, PHD, veterinary and public health entomologist, told us he only recommends EPA-registered insecticides for flea control. “There’s a lot of unproven products out there. The EPA serves as a sort of police source so these products do what they say they are doing.”
So we narrowed our list down to treatments with EPA-backed insecticides. Even better, we loved when a product used IGRs or insecticide synergists to speed up the work of its insecticides.
PetArmor Naturals for Cat Topical, Only Natural Pet EasyDefense Squeeze-On Cat Flea Control, Only Natural Pet Barrier Bites Soft Chews, Flea Away All Natural Flea Repellent for Dogs and Cats
Then we ditched any ingredients with dangerous side effects.
All insecticides carry a risk of side effects if used incorrectly, but some can be more dangerous than others. That’s why we sought information from places like the National Pesticide Information Center (NPIC), the National Center for Biotechnology Information (NCBI), the FDA, and the EPA to determine which ingredients we should avoid.
- Tetrachlorvinphos: According to the EPA and Humane Society, overexposure to tetrachlorvinphos can cause unpleasant side-effects for humans, including nausea, dizziness, confusion, and even paralysis and death. Symptoms are more likely to occur in children. This eliminated the Bio Spot and Hartz flea collars on our list.
- Propoxur: The New Jersey Department of Health and Senior Services cautions that propoxur exposure can lead to carbamate poisoning which can result in headaches, nausea, vomiting, diarrhea, muscle twitching, or death. The EPA disallowed its use after April 1, 2016, but Zodiac Breakaway Flea & Tick Collar for Cats still uses it.
- Pyrethroids: According to the Agency for Toxic Substances & Disease Registration, a subsection of the CDC, humans exposed to pyrethroids can experience numbness, itching, burning, stinging, or tingling. Pyrethroids appear on flea medicine labels as etofenprox and flumethrin. Etofenprox is found in some Adams, Bio Spot, Sentry, Zodiac, and Frontline products. Flumethrin disqualified the Seresto flea collar.
- Pyrethrins: According to VCA Hospitals, cats are more sensitive to pyrethrins and pyrethroids than dogs because they can’t metabolize the ingredient. Cat products that have pyrethrins aren’t inherently unsafe, but using them could risk overexposure if cats come into contact with pyrethrins under other conditions. Pyrethrin poisoning causes vomiting, incoordination, shaking, tremors, seizure, trouble breathing, and hypothermia. We found pyrethrins in some Zodiac, Bio Spot, Sentry, and Adams products. Removing pyrethrins eliminated shampoos and most powders and sprays.
- Selamectin: Researchers found that selamectin leaves a high amount of residue on people when they come into contact with it. This makes selamectin potentially dangerous for people who are constantly exposed to the substance. We found selamectin used in Revolution, a spot-on medication.
Adams Flea & Tick Spot-On for Cats, Bio Spot Flea & Tick Spot-On for Cats, Frontline Tritak, Revolution, Sentry PurrScriptions Plus Cat & Kitten Squeeze-On Flea & Tick Control, Zodiac Spot-On Plus Flea & Tick Control for Cats & Kittens
At this point, we realized the research was pointing us in two different directions — spot-on treatments had more robust results, but tablets were still an effective way of treating an existing flea problem. We didn’t want to cut tablets altogether — some cat owners might be less worried about prevention, and some cats might not take kindly to spot-on treatments. So we ended up looking at the top picks in each category.
To kill and prevent as many bugs as possible, use a spot-on medication.
If you’re looking for a medicine that will not just kill fleas, but will also prevent multiple types of pest, a spot-on medication is your best bet. Unlike oral flea tablets, spot-ons can use insecticides and insect growth regulators. This combination allows the medication to kill fleas and prevent them from developing or laying eggs. Spot-ons are also the only type of medication that kill both fleas, ticks, and other pests like mites and lice.
Entomologist Mike Potter says the best way to get rid of fleas is to find a product that combines an insecticide and an insect growth regulator in order to control adult fleas and suppress the development of their eggs, larvae, and pupae.
Dr. Williams agreed, explaining that IGRs mimics insect hormones to prevent them from laying eggs. For spot-ons, we wanted a flea medication that could control an infestation from the ground up, so we only kept spot-on medicines that used an insecticide and an insect growth regulator.
With so many options, we also wanted a spot-on that could protect cats from ticks. Ticks are less common in cats — but that doesn’t mean you shouldn’t take precautions.
According to the Banfield Pet Hospital State of Pet Health 2016 Report, “[Ticks] can unknowingly be on people, other animals or materials that enter the pet’s environment. Therefore, it is important to continue using flea and tick preventives on indoor pets.”
Ticks carry diseases such as Lyme disease and Rocky Mountain spotted fever, which are easier to prevent than they are to treat. They’re also prevalent across the country, but are most common in the Northeast and Great Lakes regions. If you want to protect your cat from as many pests as possible, spot-ons are the best option for you.
Activyl, Advecta II, Bayer Advantage II, Bayer Advantage Multi, Cheristin for Cats, PetArmor Advanced 2 Flea Treatment for Cats, PetLock II Flea Treatment for Cats, Vectra
If you only want to treat a flea problem, use an oral tablet.
Over-the-counter flea medications only treat fleas — they don’t prevent new fleas from developing or treat other pests. But if your cat won’t tolerate a spot-on medicine, oral tablets are a convenient alternative. Tablets work by releasing medication in your cat’s bloodstream so that fleas die once they bite. Oral medicines are easy to hide in your cat’s food, and they eliminate exposure to insecticides. You can give your cat this medication daily, but if you have a persistent flea problem at home, you might prefer the long-lasting effects of a spot-on instead.
That left us with 12 finalists.
After looking at the ingredients, we examined our remaining oral tablets and spot-ons, paying close attention to their appearance, smell, and ease of application. Our top picks are the easiest to find and apply.
We tested nine spot-on treatments:
- Catego Cat Flea Prevention & Treatment
- Frontline Plus
- Frontline Gold
- Flea5X Plus
- Cat MD Maximum Defense Cat Flea & Tick Treatment
- PetAction Plus Flea & Tick Treatment
- PetArmor Plus
- PetLock Plus Cat Flea Treatment
- Sentry Fiproguard Plus
And three oral tablets:
- Capstar Flea Treatment Tablets
- PetArmor FastCaps
- Sentry Capguard
Our Picks for the Best Flea Treatment for Cats
Frontline Plus for Cats gets our pick as one of the two best spot-ons when it comes to killing pests. It kills all stages of fleas — eggs, larvae, pupae, and adults — as well as all stages and ticks and helps eliminate chewing lice.
Its formula is safe enough to use on kittens as young as 8 weeks old as long as they’re over 1.5 lbs, in addition to breeding, breastfeeding cats. Kittens are just as susceptible to fleas and ticks – but can’t always handle the insecticides used in other topical medications. So it’s a win all around.
Application was easy too; all you have to do is point the applicator between your cat’s shoulders and squeeze. After application, you should keep children and other pets away from your cat for at least 24 hours to allow the product to dry.
All spot-ons work similarly, but Frontline’s long, snap-off applicator tip made it easier to apply. By comparison, Sentry Fiproguard Plus and PetArmor Plus require scissors, and some of the liquid leaked out.
Another Option for Long-Haired Cats We like Catego’s long, space-age applicator tip, ideal for long-haired cats. It was the easiest to apply, but it cost twice as much as Frontline and can’t be used on pregnant, nursing, elderly, or disabled cats.
This EPA-approved product uses a fipronil and (s)-methoprene combination as its insecticide/insect growth regulator combination, so it kills fleas and prevents them. Frontline starts killing fleas within four hours after application and kills 100% of fleas within 12, making it the fastest-acting spot-on in our top picks.
Each application kills and prevents fleas and ticks for a month and prevents fleas for almost twice as long — up to six weeks. Because spot-on medications are waterproof and absorb into the skin after 48 hours, they’re good options for cats that like the outdoors, and you don’t have to reapply after your furry friend gets wet.
In terms of price, Frontline is one of the more expensive spot-ons we tested at $32 for 3 applications.
From right to left: Frontline Plus, Catego, Sentry Fiproguard Plus, PetArmor Plus
A Cheaper Spot-On Medication
Sentry Fiproguard Plus is another good option. Like Frontline, this product kills all stages of fleas, some ticks, and helps eliminate chewing lice. It’s identical in packaging and label claims to PetArmor Plus, but it’s half the price.
While the formulas are similar, but we uncovered a few differences during our hands-on testing. Specifically, we found that we preferred Frontline’s clear packaging and snap-off tip. By comparisons, Sentry had to be cut open, and the medicine leaked out onto our scissors each time. You’ll have to take extra caution to make sure it doesn’t leave a chemical residue on you or anything you touch.
We noticed a range of scents too. Most spot-ons (Frontline Plus included) have a distinct chemical scent. That’s to be expected – these are chemicals after all – but Sentry’s was slightly more mild, even faintly citrus. But really, the difference is tiny, and the scent from any medicine will likely fade after a day or so.
Each application takes 12 hours to begin killing fleas and 48 hours to begin killing ticks. After application, you should allow the product to dry for 24 hours before letting your cat around other pets or children.
Sentry Fiproguard Plus was the cheapest spot-on in our top picks at $12 for three applications.
Best Oral Treatment
If you just need to treat your cat fast, Sentry Capguard, PetArmor FastCaps, and Capstar, and are all decent options. Each brand includes six tiny tablets that use nitenpyram to start killing fleas within 30 minutes. Plus, all the flea-fighting takes place internally, so you don’t have to worry about coming into contact with the insecticide.
Since these tablet don’t help prevent future generations of fleas, they’re best used as an immediate, temporary solution. You’ll give your cat a tablet up to once per day until the fleas are gone. But if you’re dealing with a true infestation (you’ll notice fleas on your furniture and carpeting), consider switching to a spot-on after the first day or talk to your vet about prescription options.
You can use these tablets with kittens as young as four weeks old and on cats weighing anywhere between 2 and 25 lbs. Each of the labels also say these products are safe for dogs and puppies, so they’re a versatile option if you have multiple pets.
All three of these oral flea medications were identical in look, smell, and packaging. The only differences between them were brand name and price, and for that reason, we recommend Sentry Capguard at $15 for 6 tablets. PetArmor FastCaps came in a close second at $16 and Capstar was the most expensive at $27.
Did You Know?
Fleas are more common in cats.
The Banfield Pet Hospital State of Pet Health 2016 Report says that fleas are almost twice as prevalent in cats than they are in dogs, making flea education an important topic for cat owners. Even if your cat stays indoors, they should still be treated for fleas. The report states, “Indoor-only pets are also at risk for fleas and ticks since these parasites can unknowingly be on people, other animals, or materials that enter the pet’s environment.”
In the United States, Washington, Oregon, Florida, Louisiana, and Alabama are the top five states for flea problems. Fleas are most common in the South and on the West Coast because they thrive in hot, wet environments.
For best results, talk to your vet.
Oral tablets can be more convenient — they can’t be washed off (or licked off) of your cat. But the oral medications we looked at only treat an existing flea problem and could be difficult for pet owners to get their cats to swallow.
Dr. Ari Zabell at Banfield Pet Hospital explained there are currently no over-the-counter oral options available for both flea treatment and prevention — the oral medications that do exist require a prescription. Topically applied medication comes in over-the-counter and prescription options too.
“Some of the current OTC medications are simply medications that were previously available only by prescription, but have since proven safe enough to be available over the counter. Prescription medications often use newer ingredients to which fleas haven’t yet developed resistance.”
While insecticide-resistance in fleas is a growing concern, some vets are skeptical. In an article from Veterinary Practice News, Dr. Michael Dryden, DVM, Ph.D. suggested that when a flea medicine doesn’t seem to work, it’s likely due to user error. “I have investigated homes that by owner description sound like there could be a resistance problem but found, when I looked closer, there was always a reason for the failure. None was ever resistance.”
To leave no room for error, read the medicine’s directions before you apply it, set reminders for when it’s time to reapply, and regularly wash your cat’s bedding and vacuum your floors.
Always take precautions when dealing with new medications.
All pets are different and can react to medications in different ways. Some cats can be sensitive to the topical medications being placed on their skin, but the same can go for oral medications too.
If your cat has allergies or other ailments that could affect how they handle a new flea medicine, consult your vet first to determine the best medication for your cat.
If you haven’t noticed an improvement in your cat’s fleas after a few weeks or if your cat experiences any side effects, contact your vet for guidance.