Lungworm in Dogs

Lungworm in UK dogs

Are you lungworm aware?

Perhaps you’ve heard of lungworm in dogs but feel vaguely confident your dog is protected. Unfortunately, complacency kills and puts your dog at risk because this potentially deadly infection has spread countrywide.

To find out if your dog is at risk, see how many of the following questions you answer “Yes” to.

  • Are there foxes in the area?
  • Is lungworm in your area?
  • Does your dog roll in fox poop?
  • Does your dog have contact with slugs and snails?
  • Do you leave dog toys out in the garden?
  • Does your dog eat grass?

If you answered “Yes” to ANY of those questions, then lungworm could pose a danger to your dog. This parasite has a complex lifecycle involving foxes, slugs, and snails; any of which are potential sources of infection for dogs. The devastating consequences of which can be haemorrhage and death from blood loss.

Is Lungworm in your area?

uk lungworm map

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What is Lungworm?

A parasite called Angiostrongylus vasorum is responsible for lungworm infections. (Actually, the common name, lungworm, is misleading because Angiostrongylus isn’t specifically a lung worm but rather a parasite that invades the heart and major blood vessels.)

Lungworm used to be a local disease, confined to small areas in the south-west of England. It is largely spread by foxes, and the unchecked rise in the urban fox population means this once rare condition is now common. Indeed, experts now warn that any dog in the UK should be considered at risk.

“The prevalence of lungworm in dogs is increasingly common.”
Ruth Willis: MRCVS, Cardiac specialist.

Imagine a Disease Designed to Kill Dogs

Imagine you are tasked with designing a killer disease to infect large numbers of dogs. What factors would you consider desirable? Here are a few suggestions:

  • Easy to catch
  • Spread locally by common garden arthropods (slugs and snails)
  • Spread over large areas by wild animals (foxes)
  • Few symptoms until dangerous numbers are reached in each dog
  • Sudden and catastrophic bleeding leading to death

Yep, that pretty much sums up lungworm.

How do Dogs get Lungworm?

Knowledge is power when it comes to minimising risk, so let’s take a quick look at the lungworm life cycle.

The dog picks up infection by eating larvae in slugs, snails, or snail-slime. The larvae migrate through the gut wall via the liver into the main vein entering the heart to reach its preferred location, the right ventricle. The adult worms produce more eggs, which hatch and migrate through the lungs, where they are coughed up, swallowed, and pass out in the dog’s poop. More slugs and snails can become infected by contact with those infected faeces or infected fox poop.

Thus dogs eating slugs are at risk, as are those that eat grass or play with toys over which a snail-trail has been left. This is because under certain weather conditions lungworm larvae can survive in the slime.

“If untreated this [lungworm] can be fatal to dogs, usually due to uncontrolled bleeding.”
Ruth Willis: MRCVS, Cardiac specialist

Lungworm Symptoms

In the early stages of lungworm infection the dog may show no signs or display only vague, non-specific symptoms such as:

  • Lack of energy
  • A cough
  • Diarrhoea

As the number of worms multiply inside the blood vessels and heart, and then start to migrate, the cough may worsen and the dog’s breathing become rapid and heavy.

More advanced symptoms of lungworm include:

  • A swollen belly
  • Distressed breathing
  • A profound lack of energy
  • Diarrhoea
  • A severe cough
  • Seizures
  • Anaemia (a condition in which there is a deficiency of red cells or of haemoglobin in the blood)

Unfortunately, the worms are well adapted to life in blood vessels and protect themselves by producing a factor which interferes with blood clotting. Once enough of this anticoagulant has built up in the blood stream, the dog may bleed heavily from minor scratches or bumps. Indeed for the dog that starts to cough blood the future is very grim indeed, and some dogs have died from minor injuries such as a broken toe nail that refused to stop bleeding, leading to profound anaemia, and death.

How is Lungworm Diagnosed?

Fortunately, vets now have a simple ‘one spot’ blood test which gives a quick Yes / No answer as to whether a dog has lungworm. This test is used not only in suspected cases but for dogs undergoing routine surgery to screen then prior to a procedure such as neutering where good blood clotting is essential. [2]

For dogs that are sick with lungworm, the vet may need to assess the damage already done to blood and the organs. To this end they may run screening blood tests to check if a blood transfusion is necessary, and an ultrasound scan of the heart to see if permanent damage has occurred.

Lungworm Treatment

Treatment is a two-pronged attack aimed at killing the Angiostrongylus whilst dealing with problems such as blood loss or heart failure. As you might suspect, treating lungworm is not without complications, one of which is dead worms in the circulation causing foreign body reactions and pneumonia.

Actual lungworm treatments are the same as the preventatives (see the next section). In addition the dog may need:

  • A blood transfusion to replace lost blood
  • Steroids to prevent the immune system going into overdrive due to the presence of dead worms in the blood stream
  • Antibiotics to treat secondary pneumonia
  • Heart meds such as diuretics to improve how the damaged heart works.

All in all it’s clear that infection is undesirable and prevention is much the better option.

Lungworm Prevention

Happily prevention is easy for the diligent owner as there are several products known to be effective at killing larvae straight after ingestion.
These include:

  • Advocate:Active ingredient moxidectin and imidacloprid.
    • This spot-on treatment is licensed for both the treatment and prevention of lungworm. It should be applied once a month, every month.
  • Milbemax: Active ingredient milbemycin.
    • This is a tablet which is licensed for the prevention of lungworm when given once a month, and as a treatment it should be given weekly for four weeks

In addition, Panacur (Fenbendazole) may be used to treat infection when given daily for 21 days.

Be Lungworm Aware

Reduce the risks of your fur-friend contracting lungworm by taking the following steps:

  • De-slug your garden (Safely of course! Take care with slug pellets)
  • Don’t leave toys or water bowls out for slugs and snails to crawl over
  • Stop your dog rolling in fox faeces
  • Use an approved preventative product such as Advocate or Milbemax, once a month, every month.

Is this a problem you were aware of or has your dog had a lungworm scare? Leave a comment and share your experiences with the DDT community.

For more extensive information on lungworm in dogs visit Lungworm.co.uk

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