Lungworm in dogs and how to prevent it

June 29, 2022 - 4 min read

This article was written for the United Kingdom market and the advice provided may not be accurate for those in the United States.

dog with snail
dog with snail

Lungworm used to be rare in the UK and confined mostly to just a few geographical regions. But it has spread rapidly.

What is lungworm?

Lungworm, or Angiostrongylus vasorum is a parasitic worm that affects dogs and foxes.

Once a dog or fox infected, the worms live in their heart and the major blood vessels to the lungs, where they cause serious health problems.

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How lungworm is spreading in the UK

By April 2020, there were more than 2,500 reported cases of lungworm around the UK by April 2020. Pet pharmaceuticals company Bayer, which produced these statistics and maintains the UK Lungworm Map says the situation could be even worse if unreported cases are taken into account.

In June 2022 the map shows that the worst areas in the UK for lungworm are The South-East of England, Birmingham and South-West Wales. Infections are not confined to these regions, with other areas across the UK also affected.

When we checked the map there were 1,709 cases within 50 miles of London, 258 within 50 miles of Birmingham and 227 within 50 miles of Swansea

You can enter your own postcode into the lungworm map to see how many dogs in your area have become infected.

The map does not say when these cases were reported so it's hard to tell how recent they are.

How do dogs get lungworms?

Dogs can get infected with lungworm when they come into contact with the slimy substance produced by slugs and snails. So either by eating the slugs and snails themselves, or by eating or licking surfaces where the slugs and snails have left a slimy trail.

Dogs can also come in contact with slime traces when rummaging around in the garden, eating grass, drinking from puddles or playing with balls and toys that have been left out in the garden.

What are the symptoms of lungworm infection?

Because lungworm affects dogs' lungs and respiratory tract, it's potentially lethal if untreated.

Symptoms include:

  • Vomiting and/or diarrhoea

  • Excessive bruising

  • Lethargy

  • Loss of appetite

  • Cough

  • Difficulty breathing

  • Spontaneous bleeding

  • Poor appetite

  • Bloody stools or urine

If you are worried your dog might have lungworm contact your vet immediately. If you have a ManyPets policy and you're worried your dog might have lungworm you can speak to a qualified vet by video call at any time of the day or night to get advice on what to do next.

Diagnosing lugworm infection can be difficult and usually requires an array of tests such as blood works, stool sample analysis and X-rays.

Canine lungworm treatment

The exact treatment a dog with lungworm needs will depend on how severe the infection is, and whether it has caused further damage and conditions.

The main treatment for canine lungworm involves deworming that targets the angiostrongylus vasorum parasite. Your vet will prescribe the dewormer.

Treatment is most successful when administered early. Even though most dogs recover fully, the disease can be lethal if not caught on time.

If you suspect your dog may have lungworm, seek veterinary help.

How to prevent lungworm

It's best to stop your dog from getting infested with lungworm in the first place. You can do this with a regular worming treatment that's effective against lungworm.

While deworming for a number of parasites is done every three months, to prevent canine lungworm, deworming is recommended monthly. Speak to your vet about the right type of canine lungworm dewormer.

There are three treatments licence for lungworm in the UK:

Advocate - this is a prescription-only spot-on from your vet. It's applied monthly and as well as killing lungworm it's also effective against fleas and some other types of worms.

Milbemax – Milbemax is a tablet prescribed by your vet that kills lungworm, as well as some other types of worm. Your vet will tell you how often your dog should be treated.

Panacur – Panacur is available as a liquid, paste or granules without prescription. You will need to work out the dosage and the frequency of doses though, so your vet's advice is recommended. It also treats some other types of worm.

You can also help your dog by making sure that any toys or water bowls kept outside the house are regularly cleaned and that there is no dog poo left in your outdoor areas.

Trying to discourage your dog from eating grass and other dogs' poo may help, too.

What kind of dogs are susceptible to canine lungworm?

Dogs of all ages can become infected but younger, more energetic dogs tend to be more curious about the world around and therefore are more likely to explore.

This puts them in more danger of coming in contact with infected slugs and snails or their slime.

Note that lungworm is not transferred from dog to dog.

Can cats get lungworm?

Cats can get lungworm too, although it's rarer than in dogs.

It's also a different species of lungworm that affects them.

Symptoms, prevention and treatment is similar to dogs – ask your vet if you're concerned about lungworm in your cat.


Derri Dunn
Content marketer

Derri is a personal finance and insurance writer and editor. After seven years covering all things motoring and banking at GoCompare, Derri joined ManyPets in 2021 to focus on pet health. She has fostered cats and kittens for Blue Cross and Cats Protection and is owned by tabby cat Diggory and two badly behaved dogs.