They can be classified as external parasites that effect the skin and ears (fleas, ticks, mites etc) or internal parasites that effect the internal body systems (worms). Fleas, worms, ticks and ear mites affect cats of all ages – including indoor cats. Most are easy to treat when caught early, and preventable with regular treatments.
Certain parasites, and skin infections that may cause similar signs like ringworm (a fungal infection, despite what the name suggests), can pass from cats to people. Prompt treatment and good hygiene are especially important in households with young children or anyone who is immunocompromised.
A regular flea and worming routine, combined with annual vet check-ups, keeps most parasites in check. Speak to your vet about the right products for your cat's age and lifestyle.
The most common parasites in cats are fleas, ticks, ear mites, roundworm and tapeworm. Of these, fleas are the most common and most cats will pick them up at some point. Fleas cause itching and skin soreness, and in kittens a bad infestation can make them seriously unwell. Ticks are less common but can carry disease, so it is important to remove them carefully and quickly if you find them on your cat.
Symptoms vary by parasite, but common signs include:
Cats can carry some parasites without obvious symptoms, so regular checks are worthwhile. Our guide to fleas and ticks has more detail on how to check your cat at home.
Despite its name, ringworm has nothing to do with worms. It’s actually a fungal infection of the skin, and it gets its name from the round, patchy marks it leaves. You may notice circular areas of hair loss, flaky or crusty skin, usually around the head, ears, or paws. It spreads easily between animals and can also pass to humans, so it’s important to get it treated quickly.
Your vet will usually prescribe an antifungal medicine and a special shampoo, with treatment usually taking several weeks. The fungus can live on surfaces and bedding for a long time, so cleaning your home thoroughly – not just treating your cat – is an important part of getting rid of it. The PDSA’s ringworm advice for cats covers diagnosis and treatment in full.
Some cat parasites are zoonotic, meaning they can pass to humans. Toxocara cati (roundworm) can in rare cases cause serious illness, including vision problems. Toxoplasma gondii, which is shed in cat faeces, poses a particular risk during pregnancy – pregnant women should avoid changing litter trays, or always use gloves and wash their hands thoroughly. Ringworm can also spread to humans through direct contact. If anyone in your household develops unexplained skin symptoms, contact your GP and inform them of your cat’s history of parasites and/or infections.
Most parasites respond well to vet-recommended treatment. Spot-on treatments, tablets, and collars are all available, and many cover multiple parasites at once. Prescription treatments that are either supplied or prescribed via a written prescription by vets are generally more reliable than over-the-counter alternatives. Never apply dog flea treatments to a cat – many contain permethrin, which is highly toxic to cats. For more guidance on choosing the right product, see our cat care and health advice.
For fleas and ear mites, treating your home alongside your cat is essential, as larvae and eggs can survive in carpets and bedding for months. Household flea sprays are effective but must never be applied directly to animals.
For every flea on your cat, there are likely around 95 more living in your home as eggs, larvae or pupae. Vacuum thoroughly before using a household flea spray, and wash all bedding on a hot wash. Treat all pets in the home at the same time.
Indoor cats are not immune to parasites. Fleas can enter the home on clothing or other pets, and ear mites can survive in a home environment for months. Even cats that never go outside benefit from a regular prevention routine.
Part the fur near the base of the tail and look for flea dirt (small dark specks that turn red-brown on damp paper) and check the ears for dark, waxy discharge.
Check when your cat was last treated for fleas and worms. Speak to your vet if you are unsure whether your current product covers all the key parasites for your cat's lifestyle.
Hot-wash your cat's bedding and vacuum soft furnishings and carpets regularly. This disrupts flea and mite life cycles and helps keep you, your home, and your cat protected.
It’s not always easy to spot fleas and ticks. Using recommended treatments can help stop them in their tracks and prevent future problems for your pets. Always speak to your vet or a Suitably Qualified Person who can advise on the best course of action.
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