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Worms will affect all pets at some stage. Many pets will be re-infected unless they are given regular, routine worming treatment. Except in rare cases, worms are unlikely to cause an animal serious harm but a heavy worm infestation will affect its general health. Getting rid of worms is simple, so regular treatment is strongly recommended, particularly as some types of worm can be passed on to humans.


What types of worms affect cats?

There are two important types of parasite worms in cats - roundworms and tapeworms. Roundworms can grow up to 15 cm long and are white in colour. They are round in cross section, whereas tapeworms are flat and ribbon-like. Tapeworms can reach up to 60 cm long. Both roundworms and tapeworms live in the cat's intestines along with two other types of smaller worm, similar to roundworms, called whipworms and hookworms.

What damage do worms cause?

Intestinal worms cause injury and loss of blood from the lining of the gut. If there are a lot of worms there may be changes in your cat's appetite, coughing, weight loss, a rough, dry coat and a 'pot-bellied' appearance. In kittens a worm infection can be dangerous, because the intestine could become blocked (although this is rare in an adult cat) and quickly be fatal. Worms can also cause diarrhoea, dehydration and anaemia, and this may make your cat run-down and susceptible to other diseases.

How are worms passed on?

Roundworms grow in the intestine laying thousands of eggs that pass out in the faeces (droppings). The eggs can survive for months or even years in the soil and need to lie in the environment for some time before they can infect another animal. They find their way into a new host either directly, when eaten by a cat or indirectly after being swallowed by a rodent that then is eaten by a cat. Inside the rodent - and sometimes in people - the egg hatches inside the gut, burrows through the intestine wall and lodges as a resting larval stage somewhere within the body. Some of these larvae also survive in the tissues of an infected cat. If that cat is female and has kittens they make their way to the cat's breast and are passed on to the kittens in the milk.

Tapeworms anchor to the intestinal wall and grow a continuous ribbon of segments - each packed with eggs. The segments gradually break off and are passed in the cat's faeces. They may wriggle like a maggot for a short time and they dry up (sometimes still attached to your cat's fur). The most common type of tapeworm moves on to a new cat by way of fleas. The next cat will become infected when it swallows an adult flea whilst grooming itself. There is also a less common type of tapeworm that uses mice and other rodents to complete its life cycle. A cat is infected when it hunts and eats the rodent.

How can I tell if my cat has worms?

Apart from the general effects on health described above, signs of infestation are to be found in your cat's faeces. Segments of tapeworm looking like grains of rice can often be seen in the droppings or in the fur around your cat's bottom. You may be startled to see them move. Roundworm eggs are microscopic.

How can worms be destroyed?

There are some highly effective treatments that will kill worms. These are available as liquids, tablet or injections. However, not all the products are equally good and some work against certain types of worms and not others. Your vet will be able to advise you on which product is best for your cat. Worms are so common that it is safe to assume that any kitten, cat with fleas or animal that regularly catches rodents will be infected. Kittens should be dosed every two weeks from four weeks to 16 weeks of age and older cats should be treated about every three months. Some cats, eg hunting cats, will need more regular treatment than others. You should discuss with your vet the most appropriate treatment regime for your cat.

Can my family be affected?

The type of roundworm normally found in cats is much less likely to cause problems in humans than that of dogs and most of the parasites found in cats are unable to survive at all in people.

What can I do to reduce the risk?

  • Regularly worm your pets.

  • If a cat uses your garden as a toilet clean up the faeces and bury them (if your cat has not done so already) or put them inside a sealed bag in your dustbin.

  • If your cat normally uses a litter tray, remove the faeces every day and disinfect the tray every week using hot water.

  • Check your cat for signs of fleas and treat them regularly using the product recommended by your vet. Fleas are more numerous in the summer and autumn.

  • Discourage your cat from hunting rodents by keeping it indoors at night.

  • Children will put dirty fingers and other objects into their mouths and this may bring them into contact with worm eggs. Make sure that they wash their hands after playing in a garden or other open areas that may be used as a toilet by cats. Remember the greatest risk of children being infected with worms is from other children not your cat.

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