Flea Infestation. Why Does My Indoor Cat Keep Getting Them?


Many cat owners are surprised to find fleas on their strictly indoor cats. While fleas need to live on a host to survive, they can find their way inside through a variety of means. Once inside a home, fleas can multiply quickly and infest cats and other pets. Understanding how fleas get on indoor cats and implementing prevention methods is key to keeping cats comfortable and flea-free.

How Fleas Infest Indoor Cats

Fleas can make their way into a home in a variety of ways, even if you only have indoor cats. Some common ways fleas infest indoor cats include:

Fleas can hitch a ride inside on other pets or humans. If dogs, outdoor cats, or other animals come into your home, they may unknowingly bring fleas in with them. Fleas can then jump off onto carpets, furniture, and of course your indoor cats.

Adult fleas can also get into a home by being carried in on clothing or shoes. If someone in the household spends time outside in grassy areas that contain fleas, the fleas can cling to socks or shoe laces and get brought indoors.

Fleas may already be present in your home. If you allow your cat access to basements, crawl spaces, or garages, fleas may have infested those areas already. They can then spread to other parts of the home and jump on your cat.

Eggs and larvae may be present in carpets, bedding, or cracks in hardwood floors from a previous infestation. Under the right conditions, these can hatch into adult fleas that will jump onto pets.

In rare cases, fleas may come in through open windows and doors from the outside environment.

Flea Life Cycle

The flea life cycle has four stages: egg, larva, pupa, and adult. Understanding this cycle helps identify key points to break the flea life progression and prevent further infestations. Adult fleas live on the cat and lay eggs that eventually fall off into the environment. These eggs hatch into larvae within 1-10 days. The larvae feed on organic debris and mature into pupae, exiting the cocoon as adult fleas in about 1-2 weeks. Newly emerged adult fleas jump onto the cat host to feed, starting the cycle again (Orkin).

Adult female fleas can lay up to 50 eggs per day and over 2000 eggs in a lifetime. These eggs readily fall off the cat into carpets, bedding, furniture, and other areas the cat frequents. Flea eggs hatch faster in warmer, humid conditions. The larvae avoid light and feed on organic matter like dried blood excreted by adult fleas. After spinning a silken cocoon, the pupal stage lasts from 1-2 weeks before the adult flea emerges. The entire life cycle can be completed in as little as 2-3 weeks, allowing populations to rapidly increase.

Knowing the flea life stages helps identify key intervention points. Regular vacuuming removes eggs and larvae in the environment. Flea control products like sprays target adult fleas on the cat before they can lay additional eggs. Breaking this life cycle is critical to preventing ongoing infestations (EcoGuard Pest Management).

Flea Prevention

It’s important to provide regular flea prevention medication for indoor cats, as fleas can easily be brought inside on humans and other pets. Flea medications like topical treatments or oral pills kill adult fleas and prevent eggs from hatching. This breaks the flea life cycle and controls infestations.

In addition to flea medication, thoroughly vacuum and wash all fabrics in the home. This helps remove eggs and larvae hiding in carpets and furniture. Use flea sprays or powders on upholstered areas cats frequent. Maintaining vigilance with prevention is key, as just a few fleas can lead to major infestations.

Ask your veterinarian for the best flea prevention plan for your cat. They may recommend year-round use of medication, even if your cat never goes outside. Consistent prevention is the best way to keep fleas from taking hold in your home.

Treating a Flea Infestation

Getting rid of a flea infestation requires attacking the problem from multiple angles. Some key treatment methods include:

Vacuuming: Use a powerful vacuum cleaner on any floors, furniture, upholstery and mattresses daily. This will suck up adult fleas and eggs andStimulate the emergence of larvae and pupae from their cocoons so they can then be dealt with by insecticides. Be sure to throw away the vacuum bag after use so any fleas don’t escape back into the home. https://www.healthline.com/health/healthy-home-guide/how-to-get-rid-of-fleas

Washing bedding: Wash your cat’s bedding at least once a week in hot, soapy water to kill fleas, eggs and larvae. Increase the frequency during heavy infestations. Also wash any bedding from pets that sleep on human beds. https://www.webmd.com/pets/kill-fleas-at-home

Carpet sprays and powders: Apply an EPA-registered insecticide spray or borax powder to all carpets and rugs. The powder may be left in place for a week while the spray should dry completely before allowing pets back on the area. This will kill off adult fleas and prevent any larvae from developing.

Flea bombs: Flea “bombs” or foggers can be used in vacant rooms to kill fleas and eggs. But they aren’t a standalone fix and need to be used alongside vacuuming, washing and topical treatments on pets. Protect yourself and follow directions carefully when using foggers.

Flea Bites

Flea bites on cats often appear around the neck, tail base and hind legs. The bites themselves will be small, red, and raised bumps on the skin. They are often clustered in groups. Flea bites are extremely itchy for cats and they will bite and scratch themselves raw to get relief.

To help soothe irritated skin and provide relief, you can apply a cold compress to the affected area several times a day. Hydrocortisone creams or antihistamines may also help reduce inflammation and itching. Make sure not to scratch or over-groom the area, as this can lead to infection. Keeping your cat’s claws trimmed can help prevent damage from scratching.

It’s important to treat the underlying flea infestation. Otherwise, the irritating bites will continue. Use flea prevention products on your cat and treat your home environment to fully get rid of fleas.

Risks of Fleas

Fleas can pose multiple health risks to cats beyond just itching and discomfort from bites. According to the Cornell Feline Health Center, fleas can transmit other parasites and diseases to cats including tapeworms and Bartonella 1. Tapeworms are intestinal parasites that fleas can carry and transmit through their bites. Bartonella is a type of bacteria that can cause an illness called Cat Scratch Fever in humans, and cats can get bartonellosis from flea bites.

Flea infestations can also lead to anemia, especially in kittens. As fleas feed on a cat’s blood, kittens may become severely anemic from the blood loss since they have less blood volume. Anemia can make cats lethargic, weak, and can be life-threatening without prompt treatment according to PetMD 2.

When to Call the Vet

In most cases, flea infestations can be managed at home with proper prevention and treatment. However, there are some situations when it’s important to contact your veterinarian:

  • If the flea infestation is very severe and your cat is constantly scratching, seems very uncomfortable, or has hair loss from scratching, a vet visit is recommended. They can provide prescription strength flea prevention and treatment options.
  • If your cat is a kitten or elderly, they are at higher risk for anemia from flea bites. Kittens and older cats have less blood volume, so flea bites can more quickly lead to anemia. If you notice any signs of weakness, lethargy, or pale gums, take your cat to the vet right away.
  • If your cat has any other health conditions made worse by flea bites, such as skin allergies or infections, it’s important to get the infestation under control quickly. Your vet can help determine the right treatment plan.
  • If you’ve tried over-the-counter flea medications but the infestation persists, prescription products from your vet may be necessary. Some fleas have developed resistance to certain ingredients.
  • If fleas keep rapidly reinfesting your home even after treating your cat, your vet can recommend products and strategies to get the infestation fully under control.

Severe flea infestations can lead to anemia, infections, and significant discomfort for cats. Contact your vet promptly if home treatment isn’t resolving the problem. They can provide prescription-strength flea prevention and treatment to relieve your cat’s symptoms and get rid of fleas.

Preventing Reinfestation

Even after treating your home and cat for fleas, you’ll need to take ongoing preventative measures to ensure the fleas don’t return. Flea eggs and larvae can survive treatment and hatch later, starting a new infestation. Follow these tips to keep fleas away:

Vacuum all floors, crevices, and furniture thoroughly and frequently, sealing and disposing of the vacuum bag after each use. The vibration and suction of vacuuming can remove flea eggs and larvae while they are still developing.

Wash all pet bedding, blankets, pillows, and throws in hot, soapy water to kill any fleas or eggs. Since fleas thrive in carpets and rugs, consider removing all floor rugs and steaming or shampooing all carpets.

Use an indoor flea spray or powder monthly inside your home. Sprays containing insect growth regulators prevent hatching eggs from developing into adults.

Treat your yard with a flea and tick spray or sprinkling diatomaceous earth, which dries out and kills fleas. This prevents them from being brought inside on shoes or paws.

Bathe your cat weekly with cat flea shampoo and apply a monthly spot-on or oral flea preventative like Revolution or Comfortis as directed. Treat any other pets in the home as well.

Continue following your vet’s instructions for topical or oral flea treatments. Most monthly preventatives kill fleas before they can lay viable eggs, breaking the life cycle.


In summary, while indoor cats are less susceptible to fleas than outdoor cats, infestations can still occur when fleas are brought inside on people or other pets. The key to prevention is using an effective monthly flea preventative on your cat. Vacuuming and washing bedding frequently will also help destroy flea eggs and larvae in your home.

If your cat does get fleas, treating quickly with a flea comb, bath, and medication is important to get the infestation under control. Eliminating fleas from your home and on your cat will take some diligence, but is important for your cat’s health and comfort. Be sure to treat all pets in the household and continue prevention year-round. With proper prevention and treatment when needed, you can keep your indoor cat flea-free.

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