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It's their job to be special
It's our job to keep them that way
Your pet plays a special role in your life. And by worming them at least every three months with Drontal®, the only wormer that kills every type of intestinal worm commonly found in UK cats and dogs, you'll be playing a special role in theirs too.

Parasitic Worms

Intestinal worms are divided into two main categories, Roundworm and Tapeworm. The Roundworm group includes the following sub-groups: Ascarids (sometimes just called Roundworm), Hookworm and Whipworm.

The great outdoors. It's where your pet can run like the wind, explore and discover… eww… these little horrors:

Back to the worms
Hookworm Hookworm
Whipworm Whipworm
Hookworm Hookworm
Tapeworm Tapeworm
Hookworm Lifecycle
Whipworm Lifecycle
Roundworm Lifecycle
Tapeworm Lifecycle
Tapeworm2 Lifecycle

A yucky fact...

Some types of adult female worms can produce

eggs per day

...and another

Some worms can grow to a staggering length

Slide to see the length that worms can reach while in the gut

Worm humans

Watch out! Worms can be bad news for humans too

Don’t be alarmed though, as this is rare. Humans can accidentally swallow the eggs of the Toxocara Roundworm in a variety of ways. For example, eggs can remain in the soil and enter your house on your shoes or on wheels. Also, your pet can pass eggs to you by licking your hands or face after grooming itself. To help reduce the risk, ensure you keep up your pet's regular de-worming and always responsibly dispose of your pet’s poos.

One of the most worrying human risks comes from the Roundworm – Toxocara. Disease is not common, however it can be devastating where it does occur, as larvae can migrate within body tissues and in extreme cases have reached the eye causing blindness.

Common worm humans

Worm hotspots

Hover over the hotspots to reveal just some of the ways your pet can become infected with worms

Even your pet's puppies aren't safe from a nasty worm infection. Some worms can lie dormant in muscle tissue until your pet becomes pregnant. Then they'll travel through the uterus or through your pet's teat and into her milk. Almost all puppies are infected by Roundworm in this way.

Some Tapeworms use fleas to get to your pet, because flea larvae eat worm eggs. A larval Tapeworm then forms inside the developing flea, which your pet can swallow. This is why it's so important to regularly 'de-flea' your pet, as well as 'de-worm'.

Once it starts to break down, poo from an infected animal – including your own pet – blends into the soil. Here worm eggs can lay dormant for over a year and be accidentally swallowed by your pet.

Mice, birds and even sheep either caught or discovered by your pet can present a risk. This is because worm eggs or worm larvae can be found in these animals, which your pet may find and feed on.

Common worm hotspots


In the early stages of a worm infection, your pet may show few, if any noticeable signs of infection. But, if the infection is left untreated, you may notice the following:

Loss of appetite

An advanced worm infection can make your pet feel bloated and may put them off their food.

Dull Coat

Because worms can cause your pet to become malnourished, they can also cause a dull coat. However, this can also be down to fleas or a poor diet.


If your pet appears to be washing its bottom more than usual, this may be down to itching caused by a worm infection.


Diarrhoea due to a worm infection is particularly common in puppies and kittens.


Scooting is when a pet drags its bottom along the ground. This can be caused by an advanced Tapeworm infection as the segments passing through the pet's anus cause itching.


Some worm infestations can cause vomiting, with worms sometimes visible in the vomit.


A pot-bellied appearance due to worms is particularly common in puppies and kittens.

It is important to remember that, in many cases, your pet may have none of these symptoms and still have a worm infection. Usually the worms will remain hidden in your pet's gut and they will not be visible in your pet's poo.


Once they've found their way into the gut, parasitic worms will survive by feeding on the contents of your pet's gut or sucking on your pet's blood. Left untreated, they can be a serious health risk. That's why it's so important to treat your pet at least every three months.

Drontal Dog XL Drontal Flavour Bone-Shaped Drontal Puppy Drontal Cat Drontal Cat XL Click to see the Drontal worm treatment range

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Data Protection Officer
Risk Management Department
Bayer plc
Bayer House
Strawberry Hill
RG14 1JA

Telephone: +44 (0)1635 563251
Email: risk.management@bayer.co.uk

Corporate Data Protection Officer of Bayer AG:

Rainer Meyer
Building K56
51368 Leverkusen

Phone: +49 (0) 214 30 2 05 22
Fax: +49 (0) 214 30 2 03 46
Email: email contact form

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Bayer plc

Registered office

Bayer House
Strawberry Hill
RG14 1JA

Tel: +44 (0) 1635 563000
Fax: +44 (0) 1635 563513

Email: animal.health@bayer.com

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