Roundworms in Pets Explained

Roundworms are one of the most common intestinal parasites seen in pets, particularly in puppies and kittens. The good news is that they are usually straightforward to treat and, with regular worming and good hygiene, they can often be prevented.

If you are worried that your dog or cat may have worms, understanding the signs to look out for and knowing when to speak to your veterinary surgeon can help you act quickly and confidently. At Vetscriptions, we know parasite control can sometimes feel confusing, so we have put together this simple guide to explain what roundworms are, the risks they pose, and the treatment options available for pets in the UK.

This article is intended for general guidance only and should not replace professional veterinary advice. If your pet is unwell or showing concerning symptoms, please contact your veterinary surgeon.

What are roundworms?

Roundworms are internal parasites that live mainly in the intestines of infected animals. They are long, pale worms that often look a little like strands of spaghetti. The most common roundworms in dogs and cats are species called Toxocara, although other types can affect pets too.

These worms feed inside the gut and produce eggs, which are passed out in the pet’s faeces. The eggs can survive in the environment for long periods, which is one reason roundworm infections are so common.

How do pets get roundworms?

Dogs and cats can become infected with roundworms in several different ways. Young animals are especially vulnerable.

Common ways pets pick up roundworms

• Puppies can become infected before birth or through their mother’s milk.
• Kittens can become infected through their mother’s milk.
• Pets may swallow roundworm eggs from contaminated soil, grass, food bowls, bedding, or fur.
• Dogs and cats that hunt may become infected by eating prey animals such as rodents.
• Pets living in shared outdoor spaces are more likely to come into contact with contaminated faeces or soil.

Because infection can happen so easily, routine worm control is an important part of preventative pet healthcare.

Symptoms of roundworms in dogs and cats

Some pets with roundworms show no obvious symptoms, especially if the worm burden is low. Others, particularly puppies, kittens, or pets with heavier infestations, may become unwell.

Possible signs of roundworms

• A swollen or pot-bellied abdomen, especially in puppies and kittens
• Vomiting, sometimes with worms visible
• Diarrhoea
• Poor growth or weight loss
• A dull coat or poor body condition
• Lethargy or reduced energy
• Changes in appetite
• Visible worms in faeces

In mild cases, pets may seem perfectly well. In more severe infections, particularly in very young or small animals, roundworms can contribute to digestive upset, poor development, and general ill health.

Are roundworms dangerous?

In many cases, roundworms are treatable and do not cause lasting problems when dealt with promptly. However, they should not be ignored.

Risks to pets

Heavy roundworm burdens can affect a pet’s nutrition and growth. In young puppies and kittens, large numbers of worms can cause more serious digestive issues and may lead to weakness or dehydration. Rarely, a very heavy infestation can cause a blockage in the intestines, which is an emergency.

Risks to people

Some roundworms, especially Toxocara species, can also pose a risk to humans. People can accidentally swallow infective eggs from contaminated soil, unwashed hands, or surfaces. This is particularly important for young children, who may play in gardens or parks and then put their hands near their mouths.

Human infection is uncommon, but because it can occasionally cause illness, good hygiene and regular worming of pets are important for the whole household.

When should you contact your veterinary surgeon?

It is sensible to contact your veterinary surgeon if you think your pet may have roundworms, particularly if they are young, small, elderly, pregnant, or already unwell.

Seek veterinary advice promptly if your pet has:

• Repeated vomiting or diarrhoea
• Weight loss or poor growth
• A very bloated abdomen
• Low energy or weakness
• Visible worms despite recent treatment
• Symptoms that are severe or not improving

Your vet may recommend a worming treatment based on your pet’s age, weight, lifestyle, and medical history. In some cases, they may ask for a faecal sample to help confirm which type of worm is involved.

How are roundworms treated?

Roundworms are usually treated with worming products that kill the parasites in the gut. These treatments come in different forms, including tablets, liquids, granules, spot-on products, and prescription-only medicines.

Choosing the right wormer

Not all wormers treat all types of worms, and not every product is suitable for every pet. It is important to use a treatment that is appropriate for your pet’s species, age, weight, and health status.

For many owners, a vet-recommended worming plan is the safest and most reliable option. If your pet has been prescribed treatment, you can browse relevant options in our flea, tick & worming collection, including products for both dogs and cats.

Treatment for dogs

Dogs may need regular routine worming throughout life, with puppies usually requiring more frequent treatment early on. If you are looking for dog-specific parasite control products, our dog flea and worming products page can help you find suitable options.

Treatment for cats

Cats also benefit from regular worming, particularly if they go outdoors or hunt. Kittens need careful early treatment, and adult cats should follow a worming plan based on their lifestyle. You can explore our cat flea, tick and worming products for cat-specific choices.

Do roundworms always require a prescription?

Some worming products are available without a prescription, while others are prescription-only medicines. This depends on the active ingredient, the type of product, and the condition being treated.

If your veterinary surgeon has prescribed a wormer or another medicine for your pet, we can help you order it safely and conveniently online. Our guide on how to order a prescription medicine explains the process clearly, and our prescription FAQs answer some of the most common questions.

How can you help prevent roundworms?

Prevention is one of the best ways to protect your pet and your family. A few simple habits can make a big difference.

Practical roundworm prevention tips

• Follow a regular worming schedule recommended by your veterinary surgeon.
• Pick up your pet’s faeces promptly in the garden and when out walking.
• Wash hands after handling pets, litter trays, soil, or faeces.
• Discourage pets from scavenging or hunting where possible.
• Keep feeding areas, bedding, and litter trays clean.
• Ensure puppies and kittens start a suitable worming programme early.

Routine parasite control is an important part of general wellbeing, alongside good nutrition, vaccinations, and regular veterinary check-ups. You can also browse our wider dog collection and cat collection for everyday health products and care essentials.

What about small pets?

Although roundworms are most often discussed in dogs and cats, some small pets can also be affected by intestinal parasites. If you have a rabbit, guinea pig, ferret, or another small animal and are concerned about worms or digestive symptoms, it is best to speak to a veterinary surgeon for tailored advice. You can also explore our small animal collection for a range of health products and essentials.

Supporting your pet after treatment

Most pets recover well after appropriate worming treatment. It is still a good idea to keep an eye on them and follow any instructions from your vet, especially if they are very young or were showing symptoms before treatment.

Aftercare may include:

• Completing the full treatment course if more than one dose is needed
• Cleaning bedding and living areas
• Monitoring appetite, stools, and energy levels
• Arranging follow-up advice if symptoms continue

If your pet has frequent digestive upset, you may also wish to speak to your veterinary surgeon about broader gut health support. For general digestive care products, you can browse our dog digestion and cat digestion products where appropriate.

Conclusion

Roundworms are common in pets, but with early awareness, sensible hygiene, and regular worming, they are usually very manageable. Puppies and kittens are especially at risk, so starting preventative care early is important. If your pet shows signs such as a swollen belly, vomiting, diarrhoea, poor growth, or visible worms, it is always wise to seek veterinary advice.

At Vetscriptions, we are here to help UK pet owners access genuine pet medicines and healthcare products with confidence. Whether you are looking for everyday parasite prevention, prescribed treatment, or helpful guidance on ordering medicines responsibly, we aim to make the process as clear and reassuring as possible.

If you would like to explore treatment and prevention options, you can browse our flea, tick & worming collection, learn more about us, or contact us if you need help finding the right product. If your pet is unwell or you are unsure which treatment is appropriate, please speak to your veterinary surgeon for personalised advice.

From all of us at Vetscriptions, we are here to support you in keeping your pets happy, healthy, and protected.