Two things you do not want to come together: cats and fleas. Fleas are prolific little bloodsuckers that can be such a pain to deal with, especially when you are caring for feral or community cats. So what’s the best flea treatment for cats? Especially cats who live their entire lives outside? And do all of this, WITHOUT breaking the bank?
As cat rescuers, animal shelters, and cat caretakers have figured out, there ARE some tricks to help you choose the best, and most cost-efficient, flea medicine available. With help from your vet, of course.
Disclaimer: I give links to pet pharmacies you can purchase some of these medications without a veterinary prescription. These medications are not made in the US and can take 1-3 weeks to ship to you. I have tried to find the most reputable vendors, but I make no guarantees. Use these products at your own risk. I highly recommend going through your veterinarian for all proper prescription medications.
Disclaimer: This post contains affiliate links. This simply means I receive a small commission on qualifying purchases. Read full Affiliate Disclosure for details. Thanks for supporting the kitties!
Cats and Fleas
In order to determine the best flea treatment for cats, you need to understand the flea life cycle itself. I’ll keep this simple because no one really cares about fleas too much, do they? Everyone just wants to know how to be rid of them!
There have been over 2,200 types of fleas identified in the world. These little insects come in many different forms: cat fleas to dog fleas to human fleas, even!
However, the most common nuisance on both dogs and cats is the cat flea Ctenocephalides felis felis. Fleas are the most common of all external parasites. Fleas can cause horrible itching, anemia, allergic reactions, tapeworms, and even infectious agents such as the bacteria that causes cat scratch fever in some people!
Did you know? A flea infestation can kill vulnerable kittens and puppies simply from blood loss? Fleas are NO joking matter!
The flea has four stages to its life cycle: egg, larva, pupa, and adult. This life cycle can be as short as a month in ideal conditions or as long as SEVERAL months.
What’s the most important to remember about fleas is the adults, which make up only FIVE percent (5%) of the population are the only fleas that are actually ON the cat (or dog). The other 95% of the population of fleas (eggs, larva, and pupa) are in the environment.
What Flea Treatments Actually Do
Flea treatments vary widely from product to product, but they are effective in similar ways.
All flea treatments kill adult fleas once they bite or after a few hours of living on your pet. Some may prevent eggs from hatching or kill eggs, too. Different flea treatments are effective against ticks and lice, some are not. Some are effective against mites, while some are not. Some treatments last a single day, and other treatments can last up to 3 months.
There are many, many different products to choose from for your pets and your cat colonies.
It is important to remember: NO flea medicine can stop eggs already in the environment from turning into larva and then pupa, and then adults, to reinfest your pet. Seeing fleas on your pet after a flea treatment is administered does NOT mean the flea medicine is not working.
Flea medicine is not prevention against fleas jumping onto your pet. This is actually a GOOD thing, especially if you have a flea infestation. After a good 1-3 months of flea treatment of ALL pets in a home, you can usually cure a flea infestation without spraying the environment. However, that will take a long while. Treating the environment should always go with treating the animals.
What’s the Best Flea Treatment for Cats?
This is going to depend on your needs! I care for a colony of cats in the barn and thus the best flea treatment for me may be something a little different than for someone who only has an indoor-only cat.
For cat caretakers, we need something that is affordable to dose multiple cats with, some of whom we cannot touch. For pet owners, the answer may lie in the most effective flea medicine available.
I make no judgments on cat caretakers who have over 100 cats to care for and thus do not use regular flea treatments. However, I urge all caretakers of smaller cat colonies to consider investing in flea medicines. It makes the cats SO much more comfortable.
Please keep in mind this post is for informational purposes so you can discuss my recommendations with your vet BEFORE trying it on your beloved pet!
Best Flea Treatment for Cat Colonies: Revolution
The best flea treatment for cats who live outside in colonies is hands-down is Revolution. If you can afford it, Revolution Plus is even better! Revolution Plus is labeled for cats only.
The reason Revolution is the better option is that it is effective against nearly all external parasites (except ticks) a cat can contract, as well as roundworms and hookworms and you can use the large dog version to save you a ton of money! If you appropriately dose the large dog version, one tube could last through 4-8 cats!
Revolution Plus is better though – if the price is no object – because it adds tick protection.
Please speak to your veterinarian about using the dog revolution and the proper dosage. NEVER give your cats the dog medication without knowing exactly what you are doing. Some ingredients are toxic to cats! Revolution just happens to be the same active ingredient in both the dog and cat products.
- Kills fleas before they lay eggs (Revolution killed 98% of fleas in 36 hours!)
- Kills ticks (Revolution Plus kills 3 species of ticks!)
- Prevents heartworms
- Kills mites that cause mange and ear mites and lice!
- Kills roundworms and hookworms
- Month-long Topical Flea Treatment
- Excellent for a large range of parasites free-roaming cats are exposed to!
- Revolution is safe for pregnant and nursing cats! (Revolution Plus is NOT!)
- Safe for kittens as young as 8 weeks and 2.5 lbs!
- Requires a prescription in the US
- If you choose to buy it non-Rx from outside the US, you can only buy up to 85lb dog doses, NOT the 130 lb dog box, which is only available as a Rx in the US.
- Price is costly per animal based on the manufacturer’s doses.
- Not useful for feral cats as you can’t get close enough to apply it!
- Revolution Plus has not been evaluated for safety in pregnant or nursing cats.
- The original Revolution is not effective against ticks.
- All products, natural or medicinal have a small risk of adverse reaction. Keep an eye on your cats. The most common reaction is hair loss as the application site, which is usually harmless.
But what about feral cats you can’t apply topical treatments on? I have a solution for that, too!
Best Flea Treatment for Feral Cats: Comfortis
Comfortis is a beef-flavored chewable tablet for cats and dogs. This flea treatment can be easily crumbled up in a feral cat’s food. You must make sure he or she eats it to be effective.
- Fast-acting! Starts killing fleas in only 30 minutes!
- Kills fleas before they can lay eggs.
- Kills 98% of fleas on cats in just 6 hours!
- Easy to administer in food for cats you cannot apply topical flea treatments to
- Effective for an entire month
- It is indicated for flea treatment only.
- It cannot be given to kittens under 14 weeks old or under 4.1 lbs.
- Not for use in pregnant or nursing cats
- As with any product, adverse reactions can occur. The most common side effect reported is vomiting.
- Use with caution if also using ivermectin.
- Can be expensive per dose. Speak to a vet about using large dog-sized pills broken into pieces!
What if you have a pet cat that stays indoors all the time?
Best Flea Treatment for Indoor Cats: Bravecto Plus
If you only have one or two indoor-only cats, then the above two options might not fit your needs. Or perhaps you care for only one or two strays in your neighborhood and want the very best flea medicine you can get. That would be Bravecto and Bravecto Plus, in my humble opinion.
- Long-lasting! (Bravecto Plus labeled for 2 months and Bravecto 3 months!)
- Bravecto can be used in both dogs and cats, while Bravecto Plus is Cat-Only!
- Bravecto Plus is effective for fleas, ticks, heartworm prevention, and roundworm and hookworm infestations for TWO months!
- Bravecto is effective for fleas and black-legged ticks for 3 months, American Dog Tick for 2 months!
- 100% of fleas are killed after 8 hours and remains effective for killing 98% of fleas
- Reasonably priced at around $20 per month of treatment
- REALLY excellent for people who forget to give their pets flea medication every month!
- It can be seriously pricey if you’re doing multiple animals.
- Not tested on pregnant or nursing cats.
- Only useful on kittens 6 months or older and over 2.6 lbs.
Bravecto Plus would also be an excellent alternative to Revolution for community cat colonies if you can afford it. Just keep in mind, it doesn’t take care of mites as Revolution does. However, Bravecto Plus does take care of ticks when regular Revolution does not! Personally, I would choose Revolution Plus over Bravecto Plus for outdoor-only cats!
Or Order Outside the US Without an Rx (use at your own risk!)
Best Flea Collar: Seresto
Public Service Announcement: Do NOT use non-breakaway flea collars on cats who live or have access outside!
I do NOT suggest using a flea collar on community or stray cats. The reason for this is that cats are NOTORIOUS for catching their collars on objects as they climb. They can DIE by strangling themselves with their collars.
If you would like to use collars on your colony cats, always use a break-away collar so the cat doesn’t strangle himself from a tree branch. Break-away collars are the only collars safe enough for outdoor cats. Enough pressure and it will snap off.
The Seresto collar has a predetermined breaking point, so it is break-away. Seresto is an expensive collar to use if you have a cat who is always losing his collar, though.
- It lasts for 8 months!
- 90% effective against fleas and ticks
- Kills AND repels fleas and ticks
- Kills fleas within 24 hours, before they lay eggs
- No Prescription Needed!
- Odorless and nongreasy
- Effective against flea larva
- Fleas and ticks do not need to bite your cat to die
- Option to buy a reflective Seresto Collar for easier visibility
- A lot of adverse reactions to the collar which cause hair loss and chemical burns. ALWAYS check your cats for a reaction.
- Expensive to purchase, but for 8 months of protection, not too bad per month!
- Only for cats and kittens 10 weeks or older
Best Flea Treatment for Immediate Relief: Capstar
If you have a greatly infested cat, I highly recommend using Capstar to kill all fleas as it starts to work within 30 minutes and lasts 24 hours. After Capstar, you can apply a monthly flea medication such as Revolution Plus or Bravecto.
- Fast-acting. Fleas start dying in 30 minutes!
- Over 90% of fleas will be dead within 6 hours
- Safe for kittens as young as 4 weeks and 2 lbs
- Expensive if used as a month-long medication and bought in bulk!
- Lasts only 24 hours
- Only effective for immediate flea relief
- It only comes in pill form
OR buy a flavored version:
Best Natural Flea Treatment: Diatomaceous Earth
I’m going to be blunt here. I am not a proponent of natural products over medicine. Why? Because when something actually works from nature, man is quick to utilize that into medicine. Most medicine and chemicals we use today originated in the natural world. Willow bark tea was used until man discovered the active ingredient: aspirin.
Natural does not equal safer. After all, cocaine comes from a plant. Morphine comes from a plant. Nightshade IS a plant! All of that could kill you.
That said, diatomaceous earth CAN kill fleas. It is nowhere near as effective as chemical sprays or flea medicines, but it can help rid both the environment and your pet from fleas. Temporarily anyway.
So what is diatomaceous earth? It is basically fossilized diatoms. Diatoms are single-celled algae that live in ponds and streams. Fossilized diatoms are made of silica, which is what is ground up to make diatomaceous earth powder. DE is used for many things, including the abrasive texture in toothpaste or metal polish. And an insecticide.
How it works is that diatomaceous earth is abrasive to an insect’s exoskeleton and it absorbs lipids from the outer layer. This allows the water inside to evaporate more rapidly, which dehydrates the insect. Often fatally. It also kills arthropods (such as insects) by causing a water pressure deficiency. It also must be food-grade particle sized (or smaller) to be effective.
DE is effective against any insect with an exoskeleton, like fleas. It is also effective against slugs and snails.
Studies on using medical-grade DE to rid cattle of worms concluded it was not effective as a dewormer.
Personally, I do not need DE in my home as all the cats who come inside are on flea treatments. And I live here in Louisiana, so doing the lawn is not very effective as it rains so much the ground is almost ALWAYS wet. However, I DO apply it in the barn to help control insects outside my place.
- Effective at killing fleas
- Not expensive
- It can be a safe alternative to flea sprays for carpet or your yard.
- Safe if accidentally ingested
- Inhalation of diatomaceous earth can cause lung issues, especially with prolonged contact.
- It can dehydrate or irritate the skin and eyes.
- Can take a while to kill fleas (anywhere from 4-24 hours to start killing fleas, depending on conditions)
- It does not work on flea eggs or pupa, also some say it doesn’t work on larva either. Only Adults.
- Very messy
- Does not work when wet
- It is not always active like medications, so reapplying every few days is required.
- Most vets do not recommend applying it directly to your pet, it dries out the skin or eyes, causes lung irritation when inhaled.
- Only effective against insects, not effective dewormer
Flea Products that are Dangerous or Don’t Work!
Never, ever use Hartz flea products! There are numerous instances where pets have died from the Hartz shampoos or spot-on treatments. I have not heard of a pet dying from any other product as I have from Hartz products.
Death is always a risk of any product, but it should be a very tiny risk. Heck, peanuts have a risk of death as a certain number of people have an allergic reaction to it, but the risk is tiny.
Do NOT buy Hartz products of ANY kind. They are currently being sued for the harm their products have caused.
No One Wants Fleas!
It’s vitally important to keep all your pets on flea control. It is also just as important that the stray and feral cat colonies we feed and get fixed get flea control, if at all possible. I do understand being unable to afford medication for 100+ cats. But if you care for a smaller colony of cats, then please consider helping our feral friends live more comfortably outside.
Do you have a favorite flea product I didn’t mention? Leave me a comment below!
Disclaimer: I am not a veterinarian. Please discuss all health decisions regarding the health of your cats and feral cat colonies with a veterinarian. This post is for informational purposes only, so that you can make informed decisions with your veterinarian. Never use dog products on cats or cat products on dogs unless your veterinarian agrees. Some dog products can kill cats!