How Do Indoor Cats Get Fleas?

Think your indoor cat is safe from fleas? This is a common misconception. Just like ants or spiders that sneak into your home, fleas can slip inside, too, hitching a ride onto your cat. 

Being aware of how indoor cats get fleas and the risks associated with a flea infestation can help pet parents take steps to protect their feline friends. It isn’t hard for one flea to become hundreds or thousands of fleas in your home, but thankfully, there are things you can do to keep them away.

TL;DR: Indoor cats commonly get fleas through “hitchhiker” transmission — when humans bring fleas inside on clothing or shoes, from other pets (especially dogs) who carry them into the home from outside, or through rodents that enter the house carrying them. Fleas can jump up to 13 inches (200 times their body length) and easily transfer between pets during close contact, with even one female flea capable of laying up to 50 eggs per day once inside your home.

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Can indoor cats get fleas?

Yes, fleas can come into your home and infect your cat, even if your kitty never goes outside. Fleas can jump more than a foot, so it’s not hard for them to leap right onto your cat’s back. Once a flea is on your cat, one female flea will lay at least 20 eggs a day, which means an infestation is not far away.

How do indoor cats get fleas?

Your cat doesn’t need to leave your home to get fleas. Fleas can enter your home through open windows and doors, by hopping a ride on other pets, on your shoes and clothing, and even through wildlife like mice.

Other pets

If your cat has furry family members — such as dogs, newly adopted adult cats, a new kitten, or ferrets — these other pets can also get fleas and then share them with your cat. If your other pets spend time outside, the likelihood of them carrying fleas into your home increases. Fleas can easily jump off one pet onto another, or lay eggs inside your home and later hatch, infecting your unsuspecting cat. 

Transmission from humans

Although humans aren’t ideal hosts for fleas, these creatures will still hitch a ride on your shoes and clothing. If you visit a pet store, cat cafe, animal shelter, animal hospital, or other environment where fleas frequent, you can bring them into your home. Fleas can bite and feed on you temporarily, but they will jump ship to find a more suitable environment in your cat’s fur.

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Rodents

Mice and other rodents are unfortunately carriers of fleas and can bring them into your home and onto your cat. This is especially true if your cat is a skilled hunter. 

Moving to a new home

New homes can come with many surprises, some of which don’t become apparent right away. Flea eggs, larvae, and pupae can be present in a home that was previously inhabited by other pets. When these life stages turn into adult fleas, your cat can become their host without having ever gone outside.

Visiting other locations

Pet stores, grooming salons, other people’s homes, veterinary clinics, hotels, and other locations that your cat may visit may also have fleas. If your indoor cat visits these places, they may leave with unwanted passengers.

Windows and doors

As with ants, spiders, mosquitoes, and other bugs, fleas can enter your home through open windows and doors. No matter how safe your cat is in your home, if your yard is frequented by wildlife or has a heavy flea infestation, fleas may come into contact with your indoor-only cat.

My indoor cat has fleas — what do I do?

If you suspect your indoor cat has fleas, you shouldn’t delay in getting them some relief — but try to avoid bathing your cat, because this is very stressful for them. To give your cat some relief and get rid of the fleas for good, follow these five steps to prevent parasites and treat not only your cat but your home.

1. Start by giving your cat a fast-acting, short-lasting medication like nitenpyram. It will start to kill the adult fleas that are biting them within 30 minutes. 

2. At the same time, a long-lasting flea treatment and preventative product should be given to prevent more fleas in the future. These products come in oral, transdermal, and collar forms.

3. Next, thoroughly clean your home by vacuuming and washing everything your cat can touch. 

4. Use an environmental-treatment spray or aerosol to kill any other adult fleas, eggs, and larvae. But keep in mind that nothing can kill them at the pupal stage.

5. Because flea pupae cannot be killed and can live in your home for up to a year, continue giving your cat a flea preventative product as directed by your veterinarian.

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Best flea prevention for cats

Fleas are not only painful when they bite, but they can also carry diseases. Because of this, preventing them is a much easier plan than trying to get rid of them after your cat gets them. Not all flea preventatives are safe for cats, so be sure to check the label and ask your veterinarian if the product you’d like to give your cat is safe.

Flea collars for cats

Historically, flea collars were ineffective and could sometimes do more harm than good. Thankfully, over the years, they’ve undergone improvements in the types of drugs used and how they are absorbed. Because of this, if you like the idea of a collar as flea prevention for your cat, there are now much safer and more effective options. However, flea collars can cause irritation or hair loss in some sensitive cats, so be sure to ask your veterinarian which flea collars would be best for your cat. 

Transdermal flea prevention for cats

The most familiar type of flea prevention for cats is a transdermal medication. These products are applied as a liquid on the back of your cat’s neck, then absorb into their system. As with some flea collars, transdermal products can cause irritation and hair loss. But different transdermal products contain different ingredients, so you may need to try a few options to find the right one for your cat.

Oral flea prevention for cats

If you are concerned about potential irritation or hair loss from collars and transdermal products, consider giving your cat a pill or chewable product to prevent fleas. Oral products vary in palatability, so make sure your cat will eat them. If your cat has an especially sensitive stomach or food allergies, discuss oral flea-preventative options with your veterinarian.

Natural flea prevention for cats

“Natural” does not always equal “safe.” Essential oils and other natural products are often dangerous to cats, and despite some effectiveness in killing fleas and their various life stages, scientific evidence shows that their use for pets is limited. Always consult your vet before using a natural preventative.

Environmental flea prevention for cats

In addition to the products you put on or in your cat, environmental flea preventatives can be used to prevent infestations. Insecticide sprays, powders, and aerosols — used indoors and outdoors — can prevent fleas from surviving in your cat’s environment.

Commonly asked questions

How to tell if your indoor cat has fleas?

Fleas most commonly bite cats on their necks and on the base of their tails. If you have a white cat, it may be easier to see fleas in these areas. But no matter what color fur your feline friend has, look for scabs on their skin and excessive scratching and grooming. If your cat can’t stop itching, use a flea comb to check for fleas and flea dirt. If you find debris but aren’t sure if your cat is just dirty, rub the debris into a wet paper towel. If the dirt where you live is normally black, but the debris is red when smeared on the wet paper towel, it is likely flea dirt, which is also known as flea poop.

How do cats get fleas indoors? 

Indoor cats most commonly get fleas from other pets, mice, or from their pet parents’ shoes or clothes that carry fleas from outside into the home. Because fleas can jump more than a foot, it’s not hard for them to hop onto your cat from another source, even if they never set foot outside.

What diseases can fleas give to cats?

Fleas can carry serious diseases, which they transmit to your cat when they bite them. Some of these diseases include cat scratch disease (CSD), tapeworms, Feline Hemotrophic Mycoplasmosis (FHM), and the plague. Thankfully, your cat can avoid getting worms and diseases by using flea preventatives.

Is there cat flea-and-tick prevention?

Yes, flea-and-tick prevention for cats does exist. Not all flea preventatives also prevent or kill ticks, though. And not all products that work on both fleas and ticks kill (or prevent) all species of ticks — so you should read product labels very carefully. Additionally, you’ll want to ask your veterinarian to recommend products that are safe for cats, because many tick preventatives are only safe for dogs.

References

“Fleas: A Source of Torment for Your Cat.” Cornell University College of Veterinary Medicine, 11 Oct. 2017, www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/fleas-source-torment-your-cat.

“Flea Life Cycle | Flea Facts & Life Stages | Orkin.” www.orkin.com, www.orkin.com/pests/fleas/flea-life-cycle. 

Franc, Michel, et al. “Direct Transmission of the Cat Flea (Ctenocephalides Felis) between Cats Exhibiting Social Behaviour.” Parasite, vol. 20, 2013, p. 49, doi.org/10.1051/parasite/2013050. 

Frank, Christina. “How to Get Rid of Fleas: Protecting Your Home and Pets - Harvard Health.” Harvard Health, 12 Nov. 2024, www.health.harvard.edu/staying-healthy/how-to-get-rid-of-fleas-protecting-your-home-and-pets. 

Rust, Michael K. “Recent Advancements in the Control of Cat Fleas.” Insects, vol. 11, no. 10, 29 Sept. 2020, p. 668, doi.org/10.3390/insects11100668.