PMD Blog – How Do I Know If My Dog Has Worms?

How Do I Know If My Dog Has Worms?

Signs to look for, which worms affect UK dogs, and when to contact your vet.

Quick Answer

Many dogs with worms show no obvious signs at all — which is why regular worming matters even when they seem well.
Visible worms or segments in the faeces or around the tail are the clearest sign, but not always present.
Other signs include scooting, pot belly in puppies, weight loss, diarrhoea, and a dull coat.
Lungworm is a serious UK parasite that needs specific prescription treatment — standard wormers don't cover it.
If you suspect lungworm, contact your vet promptly. It can be fatal without treatment.

Worms are a fact of life for most dogs at some point. The tricky part is that a dog can carry a significant worm burden without showing any visible signs — which is exactly why preventative worming exists rather than waiting for symptoms to appear.

Several different types of worm affect dogs in the UK, and they vary in how they're caught, what symptoms they cause, and crucially, which treatments work against them. Knowing the difference matters.

Types of Worm Found in UK Dogs

01 Roundworm

The most common worm in UK dogs, and particularly prevalent in puppies. Toxocara canis can be passed from a mother to her puppies before birth and through her milk. Adult roundworms look like pale, smooth spaghetti and can sometimes be seen in vomit or faeces.

Signs may include:

Visible worms in vomit or faeces
Pot-bellied appearance in puppies
Poor growth and a dull coat in young dogs
Diarrhoea or vomiting
General poor condition

Adult dogs often show no symptoms at all despite carrying roundworm. This is one reason puppies are wormed frequently from a very young age, and why regular adult worming continues throughout a dog's life.

02 Tapeworm

Several tapeworm species affect UK dogs. Dipylidium caninum is the most common and is transmitted when a dog swallows an infected flea while grooming. Taenia species can be picked up from eating raw meat, prey animals, or offal. The most visible sign is tapeworm segments — small, cream-coloured, and resembling grains of rice — found around the tail, in the fur, or in the faeces.

Signs may include:

Cream or white rice-grain-like segments near the tail or in the bedding
Scooting (segments cause irritation around the rear)
Excessive licking around the tail area
Mild weight loss in heavier infestations

If your dog has tapeworm from fleas, treating the fleas is as important as treating the tapeworm — without flea control, reinfection is likely.

03 Hookworm

Less common in the UK than roundworm or tapeworm, but present. Hookworms attach to the intestinal wall and feed on blood. They're picked up through contaminated soil or passed from a mother during nursing. Heavy infestations can cause anaemia, particularly in puppies.

Signs may include:

Weight loss and poor condition
Pale gums (anaemia) in severe cases
Diarrhoea, sometimes with blood
Lethargy and weakness

04 Whipworm

Whipworms live in the large intestine and caecum. They're less common in the UK but do occur, particularly in dogs that spend time in contaminated outdoor environments. They're picked up by ingesting contaminated soil or faeces. Whipworm eggs can survive in the environment for years.

Signs may include:

Chronic or intermittent diarrhoea, sometimes with blood or mucus
Weight loss over time
Reduced appetite
Poor coat condition

Not all standard worming products are effective against whipworm — your vet can advise on appropriate treatment if whipworm is suspected.

IMPORTANT

05 — Lungworm (Angiostrongylus vasorum)

Lungworm is increasingly common across the UK and is significantly different from intestinal worms. It's picked up by eating slugs, snails, or frogs — or by accidentally ingesting their mucus trails on grass, toys, or outdoor water bowls. The larvae migrate through the body and develop in the heart and major blood vessels.

Signs may include:

Coughing or breathing difficulties
Unusual bleeding — cuts that won't stop, bruising, blood in urine or faeces, or nosebleeds
Lethargy and reduced exercise tolerance
Weight loss and poor appetite
Behavioural changes or apparent confusion
Seizures in severe cases

Lungworm cannot be treated with standard over-the-counter wormers. It requires specific prescription treatment and, if left untreated, can be fatal. If your dog is regularly exposed to slugs or snails — or if any of the symptoms above are present — speak to your vet about lungworm prevention.

General Signs That Could Indicate Worms

Many of these signs are non-specific — they can have other causes too. But any combination of these, especially in a dog that isn't on a regular worming programme, is worth investigating:

Visible worms or segments in the faeces, in the fur near the tail, or on the bedding
Scooting — dragging the bottom along the floor
Pot-bellied appearance, particularly in puppies
Weight loss despite a normal or increased appetite
Diarrhoea, with or without blood or mucus
Vomiting, occasionally with worms visible
Dull, dry, or rough-looking coat
Lethargy or reduced energy
Pale gums (possible anaemia in heavy infestations)
Coughing or breathing changes (possible lungworm)
Unexplained bleeding or bruising (possible lungworm)

Public health note: Roundworm (Toxocara canis) can infect humans, particularly young children, through contact with contaminated soil or dog faeces. Always pick up after your dog promptly, wash hands after handling dogs or their faeces, and keep children away from areas used as toilets by dogs. This is a factual public health point — not a reason to panic, but worth being aware of.

Prevention and Treatment

Key points

Regular worming prevents most worm species from establishing themselves. The right frequency depends on your dog's age, lifestyle, and risk factors — your vet can advise. There's a separate Pet Med Direct guide on worming frequency if you'd like more detail on schedules.

Not all wormers treat all worm types. Standard products typically cover roundworm and tapeworm; lungworm requires a specific prescription product. If your dog is at risk from lungworm, ask your vet about prevention.

Pick up faeces promptly — this reduces environmental contamination and the risk of reinfection.

Treat fleas consistently if your dog has had tapeworm: without flea control, reinfection from Dipylidium tapeworm is likely to continue.

Dogs that hunt, scavenge, eat raw meat, or regularly encounter slugs and snails may need more targeted worming programmes than dogs with lower exposure — discuss this with your vet.

Contact Your Vet Promptly

You suspect lungworm — coughing, unusual bleeding, breathing changes, or behavioural symptoms
A puppy has a heavily bloated abdomen, pale gums, weakness, or is clearly unwell
Your dog is vomiting worms or passing large numbers in faeces
There is blood in the faeces alongside other signs of illness
Your dog seems to be in pain or is deteriorating quickly

Lungworm in particular needs prompt diagnosis and specific prescription treatment. Don't rely on over-the-counter wormers if lungworm is suspected.

When to Contact Your Vet

You've seen worms or segments and want to confirm the species and appropriate treatment
Your dog's worming treatment doesn't seem to be working, or symptoms are persisting
Your dog is losing weight or condition despite regular worming
You're unsure whether your current worming product covers all relevant worm types for your dog's lifestyle
You have a new puppy and want to establish the correct worming schedule
Your dog hunts, scavenges, or eats raw meat and you want to discuss appropriate parasite prevention

How Pet Med Direct Can Help

Pet Med Direct stocks worming products for dogs in the UK. Some are available without a prescription; others — including those needed for lungworm prevention and certain broader-spectrum treatments — require a valid veterinary prescription.

If your vet has recommended a specific worming product, browse the Pet Med Direct shop to check availability. Always use a product appropriate for your dog's weight, age, and the worm species you're targeting, and follow the label instructions carefully.

Some worming treatments require a valid veterinary prescription. Pet Med Direct can only supply prescription medicines after the prescription has been checked. Always follow your vet's advice and the directions on the medicine label.

Frequently Asked Questions

I found worms in my dog's faeces. What should I do?

Contact your vet or purchase an appropriate worming treatment. If possible, describe what you saw — the appearance of the worms can help identify the species. Long, pale spaghetti-like worms suggest roundworm; small rice-grain segments suggest tapeworm. Your vet can confirm and recommend the right treatment. If your dog seems unwell alongside the finding, a vet visit is the better first step.

My dog is scooting. Does that always mean worms?

Not always. Scooting — dragging the bottom along the floor — is often associated with tapeworm segments causing irritation, but blocked or full anal glands are actually a more common cause. Both can produce the same behaviour. If your dog is scooting regularly, your vet can check the anal glands as well as consider whether worms are involved.

How does my dog get worms?

Different worms have different routes. Roundworm is passed from mothers to puppies before birth and through milk, and can also be picked up from contaminated soil or faeces. Tapeworm from fleas comes from swallowing an infected flea while grooming; other tapeworm species come from eating raw or undercooked meat or prey animals. Lungworm is picked up from slugs, snails, frogs, or their mucus trails. Hookworm and whipworm are picked up through contaminated soil or faeces.

Can I catch worms from my dog?

Roundworm (Toxocara canis) can infect humans, particularly children, through accidental ingestion of contaminated soil or faeces. The condition it causes in people is called toxocariasis. Good hygiene — handwashing after handling dogs or their waste, and picking up faeces promptly — significantly reduces the risk. Other dog worms are generally species-specific and don't infect humans in the UK.

Does my dog need a prescription for worming treatment?

Some worming products are available without a prescription; others require one. Prescription wormers tend to cover a broader range of parasites or higher-risk species — including lungworm. If your vet has recommended a specific product, Pet Med Direct can supply it once the prescription has been checked. Discuss what's appropriate for your dog's lifestyle with your vet.

My dog seems completely healthy. Do I still need to worm them?

Yes. Most dogs with worms show no obvious signs, particularly with a light infestation. Regular worming prevents worm populations from building up to the point where they cause harm, and prevents environmental contamination. It's the same logic as vaccination — you don't wait for the disease to treat it.

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This this article is for informational purposes only and does not constitute veterinary advice.
If you are concerned with your dog’s health, please consult a qualified veterinarian.