What is Lungworm?

Posted in , , , , | by | on 27th September, 2016

Lungworm is the common name for a worm (A. vasorum) which infects dogs. Dogs catch it from coming into contact with infected snails and slugs and their trails. Once ingested, these worms move through the body to live in the heart and lungs. Lungworm can cause a severe inflammatory response in the lungs (similar to pneumonia) or lead to life-threatening internal bleeding, both of which are life threatening. Lungworm can also cause many other non specific clinical signs depending on the location of the larvae in the body, for example neurological symptoms such as seizures. Bleeding may sometimes only become apparent when surgery is performed, for example after spaying.

What is Lungworm?


Where can my dog catch lungworm?

Lungworm has now been found all over the UK, although the the South East (including London) and Wales are hotspots. In our area of London, access to Richmond Park, Wimbledon Common or the countryside would increase the risk of exposure, although your dog could be exposed anywhere that snails and slugs live.

How do I prevent my dog catching lungworm?

The good news is that a monthly anti-parasite preventative can prevent lungworm. These are only available on prescription from a vet. They come in either oral or top-spot form. Here at Molly and Max we feel that it is very important that all dogs living in London are given monthly preventative treatment. Regular worming treatment such as Drontal (which treats other worms) unfortunately will not prevent lungworm.

If your dog comes from a country where heart worm is endemic (such as the US, Southern Europe and Australia) and you are not sure that your dog is up to date with heart worm prevention, then your dog will need a heart worm test prior to starting lungworm prevention.

What are the clinical signs of lungworm?

The most common clinical signs (or symptoms) are:

  • coughing
  • diarrhoea and vomiting
  • lethargy
  • weight loss
  • excessive bleeding
  • seizures
  • weight loss
  • loss of appetite
  • difficulty breathing/ laboured breathing

Sometimes a dog will present as generally unwell, with no specific symptoms.

How is lungworm diagnosed?

There are two routine tests for lungworm, a blood test and a faecal test (although routine faecal testing is unlikely to diagnose lungworm). Lungworm may also be diagnosed from a ‘tracheal wash’ which is where a sample is taken from the airways, under general anaesthetic. No test is 100% sensitive, so it is possible for a dog to test negative even when infected. X-rays may be suggestive of lungworm if there is inflammation in the lungs. Sometimes clinical signs together with response to (presumptive) treatment are the only way to diagnose lungworm.

If my dog catches lungworm, can it be treated?

Lungworm can be treated, but it is not uncommon for dogs to develop severe inflammation in the airways as the larvae die, leading to breathing difficulties. This response to treatment can be life-threatening. However, it is very important that dogs are treated for lungworm as the condition will only get worse if not treated. Dogs which already have respiratory signs or other severe signs are often given a gentler, slower treatment and hospitalisation is often required.

But my cat has been diagnosed with lungworm- is that the same thing?

Cats can get lungworm too, but of a different species. Cats catch lungworm through hunting. Regular worming should help prevent feline lungworm.