Lungworm in dogs

Lungworm was once rare in the UK but is becoming more common, so it's important to know what causes it and how you can prevent it.

Brown dog sniffing grass outside

What is lungworm?

Lung worm is a type of parasitic worm that can infect dogs. Unlike other intestinal worms such as tapeworm and roundworm, adult lungworm travel around a dog's body and can damage their lungs and other major organs - causing fatal consequences if left untreated.

How do dogs catch lungworm?

Lungworm larvae live in snails and slugs, as well as the waste from infected dogs or foxes (which is where the slugs and snails pick it up from).

When these are eaten, either intentionally or accidentally, the lungworm larvae are ingested into the dog’s system. The larvae can also be picked up from snail and slug slime, so any dog toys or bowls left outside can pose a risk. Frogs can also become a host for the larvae.

Once a dog becomes infected, the larvae mature and move around the body, eventually ending up in and around the lungs. The adult lungworm then lay eggs which mature into more larvae which is subsequently coughed up, swallowed and exit the body via the dog’s waste, thus starting the cycle again.

This cycle of infection means that lungworm can easily spread within dog communities, so prevention is key.

The effects of lungworm

Lungworm can cause cardiac and respiratory diseases and can be fatal in severe cases. Many dogs won’t show signs of lungworm for some time, causing it to go undiagnosed in many cases.

Symptoms of lungworm include:

  • excessive bleeding
  • unexplained or excessive bruising
  • coughing
  • difficulty breathing
  • loss of appetite
  • vomiting and/or diarrhoea
  • weight loss
  • tiredness and depression
  • pale gums
  • seizures.

How to treat lungworm

If you think your dog has contracted lungworm, contact your vet immediately.

Diagnosing lungworm can be tricky; your vet will carry out a number of diagnostic tests, such as taking blood and waste samples to see if any eggs or larvae are present. They may also conduct a chest x-ray or insert a tiny camera into your dog’s windpipe to find evidence of the parasite.

These tests will help your vet decide which course of treatment best suits the needs of your dog. Occasionally, lungworm can be killed off by changing your parasite prevention routine.

However, if there are signs of bleeding, blood transfusions and a stay in hospital may be required. There could also be a chance of permanent damage, so prevention is essential.

How to prevent lungworm

Prevention is better than treatment. Using effective lungworm prevention as part of your ongoing parasite treatment is the best way to protect your dog. Speak to your vet about the best option for your dog and for more information about high-risk areas.

If your vet confirms that you live in an ‘at-risk’ area of the UK, be extra-vigilant when out walking with your dog to stop them from eating slugs, snails and faeces. Always remember to pick up after your own dog and wash any toys and bowls that have been outside to reduce the risk of infection.

Speak to your vet for advice on protecting your dog against lungworm.

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