LUNGWORM: A BRIEF BUT ESSENTIAL GUIDE TO THE FACTS

We refer to lungworm disease caused by the worm Angiostrongylus vasorum, an emerging disease in the UK, causing potentially fatal symptoms in dogs. It first emerged in France but has since spread to many countries in Europe, Africa and the Americas. It is endemic in several parts of England and a small handful of suspected cases have now occurred north of the border in Scotland, since the first reported case in the central Scotland in 2008.

With the recent alterations in our climate, it is only a matter of time before we experience increasing numbers of lungworm cases in Scotland, and vets are on high alert to correctly diagnose this condition. Championvet,com is aware that an increasing number of our clients are concerned about this disease, spurred on in part by recent high profile television campaigns.

The main risk to wild foxes and dogs in the UK is the consumption of infected snails and slugs in the garden.

Although these creatures give off a foul tasting substance to prevent them being eaten some dogs appear to ignore this! Some of these molluscs are very small and accidental consumption can occur. Also contact with the slime trail in food bowls or on toys may be sufficient to cause infection.

THE LIFE CYCLE OF THIS PARASITE

When describing parasites we often refer to the lifecycle, which really describes the way the parasite moves from one type of host to the next. During these phases in the parasite’s life it takes on different forms, adapted to the “host” in which it is living at the time. We refer to “larvae” of the parasite, indicating the immature forms, and these are often given an “L” number to describe the stage of larvae.

Snails and slugs pick up L1 larvae in the ground and these develop into L3 forms. Once the snail is consumed by the dog the L3 grows to an L5 and migrates from the dog’s gut to the pulmonary artery via the bloodstream. The pulmonary artery is a large blood vessel attached to the top of the heart leading to the lungs. The L5 grows into the adult parasite in the pulmonary artery and lay eggs which move to the lungs via the bloodstream. In the lungs small nodules are formed containing eggs and larvae – these nodules cause many of the symptoms of lungworm disease by damaging the lungs.

Next, the eggs hatch into the L1 which are coughed up by the dog into the mouth and then swallowed back into the guts. They are passed out in the stools onto the ground where they are consumed by the snails and slugs. The lifecycle is thus completed, as you will see by reading again from the top of the last paragraph!

AND SO TO YOUR DOG………

Lungworm disease in dogs often affects young dogs less than two years old and is often a chronic disease, lasting months or years. However, it will occasionally cause sudden death.

It can manifest as weight loss, breathing difficulties and coughing up blood, vomiting, persistent bleeding,  stomach and back pain, fits, paralysis, circling  and heart failure.  Please remember that these symptoms occur with many other diseases and it is imperative you allow your vet time to make the correct diagnosis. Lungworm is still uncommon in Scotland, whereas other causes of these symptoms are far more common!

Your vet might use a variety of diagnostic methods to diagnose diseases showing these symptoms. These include blood samples for DNA, analysis of stool samples for eggs and larvae, chest x-rays and bronchoscopy.

Once diagnosed your vet might chose to use a spot-on treatment called Advocate. In tests this is effective in 85%  of cases after the first application and 100% of patients after two doses a month apart. A drug called Panacur can also be used, effective in 91% of cases after the first dose. A simple worming tablet, Milbemax, given weekly for four weeks, can also be effective.

PREVENTION OF LUNGWORM

The following advice will help you prevent potentially fatal lungworm disease in your dog:

Collect and dispose of your dog’s faeces regularly

Worm your dog at least every 3 months using a wormer effective against lungworm, such as Milbemax

Prevent contact with, and consumption of, snails and slugs

We suggest you treat your dog monthly with the Advocate spot-on treatment, available on prescription from your vet. Unlike worming tablets which “aid in the prevention” of the disease at the standard dosing interval, Advocate is licensed to treat lungworm using the standard monthly dosing regime.

ADVOCATE : Since Advocate also prevents fleas, roundworms, mange mites, ear mites and heartworm, it is a pretty comprehensive parasite control regime on its own. Therefore, only the occasional additional treatment against tapeworm is required for comprehensive parasite control – your vet at Championvet.com will advise you on this.