How Can a Strictly Indoor Cat Get Fleas?

Strictly indoor cats can still get fleas.
i Cat sitting on window sill image by Jorge Moro from

Why's your cat scratching himself like crazy? He's strictly an indoor pet -- there's no way he caught fleas, right? Wrong. Fleas are career hitchhikers. They sneak inside through windows or on other animals ... or even on you. Fleas are hard to evict, but a combination of treatments can help.

Vagabonds & Hitchhikers

Even though your cat is strictly indoors, he can get fleas via indoor-outdoor pets, outdoor animals at a window or from your clothes. Tiny, brown and wingless fleas are pint-sized jumpers whose patronage breeds itchy discomfort. The cat flea, ctenocephalides felis, is the most common external parasite in cats and dogs. (Interestingly, ctenocephalides canis -- i.e. dog fleas -- usually afflict squirrels and poultry.)

They range from the size of a pinhead to an eighth of an inch long, and they'd love nothing better than take up residence on your pet. Cat fleas thrive in warm, humid climates.

The Scratching and the Damage Done

Cats frequently scratch themselves, but the kind of scratching instigated by fleas is in a category of its own. Incessant scratching leads to open wounds that, in turn lead to infection.

Fleas are also disease vectors for bacteria. Tapeworms? Check. Cat-scratch fever? Sure thing -- cats become dealers after being bitten by carrier fleas. Cat fleas can also foster a murine-like typhus disease that affects humans.

Although fleas leave marks, they don't bite, technically speaking -- they suck blood through skin. This poses special risk to kittens, who are more apt to develop anemia as a result.

Infestation Defenestration

The only way to end flea infestation is to remove them from your cat and your home. Despite the variety of commercial flea-killing products, this is harder than it sounds. Clean and vacuum your home thoroughly. Wash all fabric and carpet with flea shampoo. Consider hiring a professional exterminator.

Clear cat fleas and their waste from your cat's fur with a flea comb. Use topical or oral flea-killing medications to free him of infestation. Read all labels thoroughly -- some dog-safe products are toxic to cats.

Comeback Kids

Much like the proverbial cat that came back the very next day, flea infestations often return. Recheck your home for external sources -- for examples, animals at windows -- and internal sources, such as indoor-outdoor pets and materials and fabrics in crawl spaces.

Recheck your cat. The back of his neck and the base of his tail may have residual eggs -- these are the two spots he can't reach. Flea colonies are often densest where your pet sleeps.

Clean your house and treat your cat again. Follow all directions for flea treatments, including timetables, which help prevent accidental poisoning.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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