All pets will be affected by worms at some stage in their
life and many will be re-infected unless they are given regular, routine
worming treatment. Getting rid of worms
is relatively simple and inexpensive so regular treatment is strongly
recommended, particularly as some types of worm can be passed onto humans.
WHAT SORT OF WORMS AFFECT DOGS AND CATS?
There are two important types of parasitic worms in dogs –
roundworms and tapeworms. Roundworms can
grow up to 15cm long and are white in colour.
As their name suggests they are round (like string), whereas tapeworms
are flat (like ribbons). Tapeworms can
grow up to 60cm long. Both roundworms
and tapeworms live in the dogs intestines along with two other types of smaller
worm (similar to roundworms) called whipworms and hookworms. There are also parasitic worms that can live
in the dogs lungs, heart, stomach or bladder.
HOW CAN WORMS BE DESTROYED?
There are some highly effective treatments which will kill
worms. These are available as liquids,
pastes, tablets, powders or spot-ons.
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 will be best for
your pet. Worms are so common that it is
safe to assume that all puppies and kittens, pets with fleas, and animals that
regularly catch wildlife will be infected.
Puppies and kittens should be treated with wormers every 4 weeks, from 4
weeks to 6 months of age, and older pets should be treated either monthly or
every 3 months depending on the product being used. You should discuss with your vet the most
appropriate treatment regime for your pet.
Immature worms can be passed from a mother to her offspring,
whilst they are still in the womb or via the milk. Roundworms grow in the intestine of young
animals, laying thousands of eggs which pass out into the faeces. Most adult animals develop a degree of
immunity and do not pass eggs but some continue to do so throughout their life.
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 dog or cat) or indirectly, (after being
swallowed by a rodent which is then eaten by the dog or cat). Immature worms also survive in the tissues of
an infected animal and can develop again if a female becomes pregnant.
Treatments for roundworms usually kill all adult worms in
the intestine but do not have any long lasting effect. This means that pets can easily be
re-infected. It is not easy to tell if
an animal has been re-infected so treatment is usually given at regular
intervals to remove any worms present.
It is likely that young pets will have roundworms and so treatment
should be started at 5 weeks of age and continued at the recommended interval
for the product used (usually every 2-4 weeks) until adulthood. Then, depending on the product being used,
preventative treatment should be continued throughout life. There are many products for routine worming
against roundworms – ask your vet to recommend a suitable product for your pet.
Tapeworms are anchored by their head to the intestine wall
and grow a continuous ribbon of segments, each packed with eggs. The segments gradually break off and are
passed out in the faeces. These segments
look like grains of rice and may wriggle like a maggot for a short time before
they dry up (sometimes still attached to your pet’s fur). The most common type of tapeworm moves on to
a new dog or cat by way of fleas. Immature
fleas pick up infection from faeces from the environment and pets are then
infected if they accidentally swallow an adult flea during grooming. There is also a less common type of tapeworm
which uses mice, other rodents and rabbits to complete its life-cycle. This parasite lies dormant in the muscle or
other organs of a small rodent or rabbit and cats are infected if they eat these animals.
There are many products for routine worming against
tapeworms – ask your vet to recommend a suitable product for your pet.
HOW OFTEN DO I NEED TO TREAT MY PET?
This depends on some extent on your individual
circumstances. Some cats, ie indoor
cats, may never be exposed to worms and so do not need repeated treatment once
worms have been eliminated as a kitten.
The products usually used to treat worms do not have any
persistent action so pets may become re-infected immediately after treatment
. Most vets recommend treating pets
every 3-6 months but dogs and cats that do a lot of hunting may need to be
treated more frequently. You should ask
your own vet for advice on the best way to control infection in your pet.
ARE ANY OTHER WORMS A PROBLEM?
There is a kind of roundworm (Angiostrongylus) that can live
in the blood vessels of affected pets.
The disease, known as angiostrongylosis, is caused by a type of lungworm
that is becoming more widespread in the UK.
Lungworm is a life threatening disease, spread by slugs, snails and
occasionally frogs in your garden. Foxes
can also become infected and play a role in the spread of infection. Other worms that live in the lungs or
respiratory system (Aelurostrongylus in cats and Filaroides in dogs) can also
cause coughing. Special tests are needed
to identify infection with these parasites but if your vet suspects infection,
they can prescribe a medication that will be effective in killing the parasites
Hookworms and whipworms are rarely seen in pet dogs and cats
in this country but may occasionally be seen where large numbers of dogs are
kennelled together. Infections with
large numbers of worms may result in diarrhoea and weight loss. Many of the routine drugs used for removing
other worms are also effective against these.
If you travel abroad with your pet they will need to be
treated to remove all tapeworms 24-48 hours before returning to the UK. This is to prevent your pet importing
diseases into the UK. A vet abroad will
need to sign a certificate to indicate that this treatment has been carried
HOW ELSE CAN I PROTECT AGAINST WORMS?
Apart from regularly worming your pets, there are a number
of other measures which can stop worms being passed on from pet to pet, or from
pets to people. If your dog uses your
garden as a toilet, clean up your faeces and bury them or put them inside a
sealed bag in your dustbin. Check your
dog for signs of fleas and treat them regularly using the product recommended
by your vet. Fleas are more numerous
during summer and autumn, although they will survive all year round in
centrally heated homes. 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 any open areas which may have been
used as a toilet by dogs. Remember the
greatest risk of children being infected with worms is from other children, not