How do I recognise and get rid of fleas on my cat?

The cat flea (Ctenocephalides felis) is the flea you find most often on cats and dogs across Europe. It is a small, flat insect without wings, a few millimetres long and reddish-brown to dark.

Only the adult flea lives on your cat. The eggs, larvae and pupae are in the home: in bedding, carpets, sofas and cracks in the floor. As a rule of thumb about 5% of a flea problem is on the cat and 95% is in the home.

A flea starts laying eggs about 24 hours after its first meal, with estimates of 20 to 50 a day. The eggs are not sticky and drop off your cat where it rests. The whole cycle from egg to flea usually takes 3 to 8 weeks in a home, shorter when it is warm and humid and much longer when it is cool and dry.

Larvae avoid light and hide deep in carpet and bedding, where they feed on flea dirt (dried, digested blood). Then they spin a cocoon.

Pupae can wait in their cocoon for weeks or months and hatch when they feel warmth, vibration or the breath of a host. That is why fleas can appear in a home that was empty for a while, or keep showing up after treatment has started.

Fleas are not related to ticks, but they live in a similar way and are often treated together.

Cats pick up fleas from other animals, from the garden, from wildlife and from your own home if fleas or pupae are already there. Fleas can also be carried in on shoes and clothes.

An indoor cat can get fleas too: through people, through a dog that goes out or through mice. In a heated home with floor coverings fleas can breed all year, not only in summer.

Fleas are more common in the warm months, but cats are found with fleas all year round, with seasonal peaks.

Fleas are not a sign of a dirty home. After a holiday or a move many pupae can hatch at once, because people and pets are back in the house.

The clearest sign is a cat that scratches, bites or licks much more than usual. You may also see bald or rough patches, small red bite spots, scabs and a cat nibbling at its back end. But many cats show very little, even with fleas.

Comb your cat with a fine flea comb over a sheet of white paper. Comb the lower back, the base of the tail, the belly, the neck and behind the ears. Fleas and flea dirt are most often found on the lower back and around the tail base. Black specks on the paper? Put them on damp white paper. If they smear reddish-brown, it is flea dirt, digested blood. Sand or ordinary dirt does not change colour. With a dark coat, comb onto a white towel and test what falls.

Finding flea dirt but no fleas still means fleas are feeding on your cat. Cats lick fleas away, and an allergic cat can react strongly to very few fleas. Bites on your own ankles or arms can be the first sign that there are fleas in the home.

Combing is the most sensitive home check, but it does not remove all fleas by itself.

Flea allergy is one of the most common skin problems in cats. The cat reacts to proteins in flea saliva, so a few bites can cause days of itching. Typical signs are tiny crusted bumps (miliary dermatitis), hair loss, and moist or crusted skin on the lower back, tail base, neck and belly. Scratching can open the skin and lead to an infection. Only a vet can confirm a flea allergy.

A heavy flea burden can cause anaemia (blood loss), mainly in kittens, but also in old or weak cats. A cat flea takes a little blood every day, which adds up in a small body. A kitten with fleas that is weak, cold or pale needs a vet right away.

Cats swallow fleas while grooming. Fleas can carry the larvae of the flea tapeworm Dipylidium caninum, so a cat with fleas can also get tapeworm. Signs, if any, are rice-like segments around the tail or in the stool, and scooting. Fleas can also carry Bartonella henselae, the cause of cat scratch disease in people. People mostly catch it from scratches or bites of an infected cat, and flea dirt on skin wounds can add to it. Do you have weak immunity? Then ask your doctor.

It is hard to avoid fleas completely all year. So your vet chooses a plan with you based on risk: how much time your cat spends outside, whether it meets other animals, how many animals live in your home and whether it is allergic to fleas.

An indoor cat that goes out little or not at all is at low risk. Regular combing and a good look are still wise, and you treat straight away if you find fleas. Cats that go outside regularly need regular preventive treatment with an authorised product, at the interval on its leaflet, plus frequent vacuuming where the cat rests. Homes with several animals, and shelters and catteries, usually need year-round protection of every animal. That is what vets commonly advise.

Treat every cat, dog and rabbit in the home at the same time, each with a product made for that species. Choose products that are authorised for sale in your country and that list their ingredients. The country block below says how to check. Wash your hands after handling pets and after any flea or tick treatment, especially when there are children.

Do you have fleas? Without regular flea control it takes at least 3 months before the problem is under control, sometimes much longer. Before a holiday, a cat protected with a suitable product catches the fleas that hatch while you are away, so they die before they bite and lay eggs.

Vets commonly use spot-ons (liquid on the skin of the neck, where your cat cannot lick it), tablets and sometimes collars. What suits depends on your cat's age, weight and health, other pets, outdoor access and any flea allergy. The vet chooses, this page does not.

Active ingredients vets name include fipronil, imidacloprid, dinotefuran, selamectin, nitenpyram, spinosad and the isoxazolines. Some are prescription only. Spot-ons spread over the skin and can take 12 to 36 hours to reach full effect. Some tablets work within hours. This is information, not a recommendation.

Nitenpyram tablets kill the fleas on the cat within hours but have no lasting effect, so the home still needs treating. The label notes that cats may scratch more in the first hour as the fleas react. Spot-on labels give the length of protection, for example up to about 4 to 5 weeks for two fipronil products. The right interval for your cat is set by the label and your vet.

Collars are used for prevention. One studied collar was reported to control fleas for up to 8 months, but collars were long used with little published evidence. Many cheap collars protect mainly the neck and head, and a collar without a safety release can catch on things.

Some products also contain something that stops eggs and larvae from developing. Flea shampoos and powders give no lasting effect, and powders can be licked off. A bath removes some adult fleas but does nothing for the eggs and pupae in the home. A flea vaccine does not exist.

For a flea-allergic cat the main treatment is strict, long-term flea control, even when you see no fleas. The vet may add short courses against the itch and antibiotics for an infection. Tapeworm is treated by the vet with an anti-tapeworm medicine plus flea control to stop reinfection. A general wormer does not always cover tapeworm, so ask. Combing and washing bedding help, but are not a replacement for a treatment that kills the fleas.

Treat your cat and your home at the same time. If you only treat the cat, the eggs, larvae and pupae in the home start the cycle again.

Vacuum floors, rugs, sofas, your cat's bed and the places under furniture often, and throw out the contents of the vacuum right away. Wash your cat's bedding, blankets and washable covers hot (60 degrees is often given). Steam cleaning alone is not enough: the heat and vibration can make the remaining eggs hatch.

Normal housekeeping on its own does not clear an infestation, because larvae hide deep in carpets and floor cracks.

For the home, vets describe sprays or other home products, often with something that stops larvae developing. Use them away from your cat, follow the label and keep your cat out of the room until it is dry and aired. For a heavy infestation a licensed pest control firm can treat the house.

It takes time. After treatment starts, new fleas keep hatching from the home for weeks, and you may still see some fleas on your cat for up to 8 weeks while they die. Fresh flea dirt should stop after about 8 to 12 weeks of consistent treatment.

The most common reasons: not every pet treated, the places where your cat rests not treated, the product given too late or for too short a time, and washing or swimming that reduces some spot-ons. Resistance is much less often the cause than people think.

Old flea dirt can keep showing for one to two weeks after the start as your cat grooms it out. That alone does not prove the product failed. If you still see fresh flea dirt after weeks of correct use, see the vet rather than adding a second product yourself. Stray cats and wildlife outside can also keep giving your cat new fleas.

Kittens are at the highest risk from a heavy flea burden, because they can become anaemic. A weak, cold or pale kitten with fleas needs a vet right away.

Flea products are not for every young kitten. Labels set a minimum age and weight. For example, two fipronil products say not under 8 weeks or 1 kg, and a dinotefuran product says not under 0.6 kg. Never use an adult product on a kitten that is too small. For kittens too small for a product, combing, washing the bedding and treating the mother and the home are what is usually described. Ask your vet what is safe for your kitten.

For pregnant or nursing cats and for sick or recovering cats, several labels say the product should only be used after the vet has weighed benefit against risk. Never give a flea product to a very young or sick cat unless the vet has said it is safe.

Many flea and tick products for dogs contain permethrin. Cats cannot break it down well, so it builds up and poisons the nervous system. Dog-strength products contain far more permethrin than products made for cats.

Most poisonings happen when an owner puts a dog spot-on on a cat, or when a cat grooms or sleeps against a dog that was treated recently. For some cats one drop, or licking an empty packet, can be enough.

Keep your cat away from a treated dog until the coat is dry. One animal welfare charity gives 72 hours of keeping them apart and stopping licking. Leaflets for dog products say the same sort of thing about keeping cats away until the coat is dry.

Signs start within hours but can take up to 2 to 3 days: tremors, twitching, drooling, wobbling, seizures, vomiting, collapse, breathing trouble, a cold cat. This is an emergency. Prompt treatment by a vet usually leads to recovery.

Be careful too with home and garden sprays that contain permethrin or pyrethrin when a cat lives in the home. Tea tree and other essential oils are not safe flea remedies for cats either.

Ticks are not insects. They sit in tall grass and bushes and attach to the skin. A small dot on the skin that grows can look like a wart. Ticks can carry diseases such as Lyme disease. In cats this is rare, but the sooner a tick is removed the better.

In tick season, check an outdoor cat every day after it has been out. ESCCAP describes removing a tick with a tick removal tool, not squeezing the body and not using oil, alcohol or ether. Some guidance says to have the vet remove it, because mouthparts left behind can cause an abscess. If you are unsure, ask your vet to show you. Dog tick products are not for cats.