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Lungworm in Dogs

Protecting your Pooch from the Effects of Lungworm

What is Lungworm?

Lungworm is a type of parasitic worm, (known as Angiostrongylus Vasorum) which affects dogs and foxes. Once dogs are infected, adult lungworms live in their heart and the major blood vessels supplying the lungs, where they often cause a host of potentially serious problems.

How is Lungworm Spread?

Slugs and snails are the culprits! Wet spring months will usually mean an influx of the slippery suckers and they all have the potential to carry the dangerous lungworm parasite.

When dogs rummage through hedges or undergrowth, eat grass or drink from a puddle, they can end up eating these slugs or snails either accidentally or on purpose. Although slugs and snails can secrete foul-tasting substances that prevent them from being ingested, some dogs will ignore these warnings. Also, any contact with the slime trail in outdoor food and water bowls, even over toys left out in the garden, can be enough to cause infection too.

Unlike many diseases, however, lungworm is not actually passed directly from dog to dog. The worm needs slug and snail hosts in order to grow and develop, and it's from eating these that infection may occur; the dog can then pass the lungworm larvae in its faeces.

The more infected slugs and snails eaten by dogs, the more likely disease is then rapidly spread within canine communities.

Effects of Lungworm

After the dog has been infected, lungworm usually causes progressively worsening signs of cardiac and respiratory disease, such as coughing (often at 'extremes' of exercise); as well as causing haemorrhages in lungs, liver, intestine, eyes, and spinal cord, but also pretty much anywhere in the body. If left untreated, it can be fatal in severe cases.

Signs of Lungworm

Signs of lungworm disease are vague, and easily confused with other illnesses, including weight loss, breathing difficulties, coughing (especially bringing up blood), lethargy, poor blood clotting/persistent bleeding – for instance if your dog gets a minor injury it may bleed for longer than normal, general sickness, circling, stomach and back pain, poor appetite, vomiting, and diarrhoea.

Lungworm is often a chronic disease, lasting months, even years. However, it will occasionally cause sudden death. Even changes in behaviour, such as depression, tiring easily, and seizures can indicate infection, with mild cases often remaining totally unnoticed by owners.

Vets can also examine a sample of the dog’s faeces under the microscope to help diagnose lungworm, although this isn’t 100% reliable as there aren’t always lungworms present in every sample. They may also carry out blood testing, and x-rays of the chest.

Lungworm Becoming More Common...

Lungworm is what we call an 'emerging' disease: it's gradually becoming more common. Until recently it only appeared in select 'hot spots' in the south of the UK, but over the last few years, it's been successfully identified in various parts of the country. It's unclear exactly what's caused this spread (and that of other parasites, including ticks), but increased movement of pets around the country, and abroad, as well as greater contact between wildlife and the urban environment are all thought to be major factors in the increasing spread of the disease.

Not every snail or slug carries the disease and lungworm's geographical limitations means infection is currently relatively uncommon, but it does rear its head from time to time; and in extreme cases, causes death of infected patients, so it is potentially extremely serious.

What to do...

If you're concerned your dog has picked up lungworm, is displaying signs of the disease, or is at risk from lungworm infection, then call your vet immediately. Lungworm treatment is widely available from your vet and extremely easy to administer. Once diagnosed and treated, most dogs make a full recovery and, like all diseases, the key to successful treatment is acting on the symptoms early on.

Killing lungworm is relatively simple and involves making sure your routine anti-parasite preventative treatments administered to your dog are appropriate. No invasive or expensive treatments are required when disease is caught early. However, the more advanced the effects or level of infection, the more significant the permanent damage is likely to be, so the more costly any veterinary treatment required will be.

Can I Prevent My Dog Catching Lungworm?

Your vet will be able to provide you with some simple treatments that you can apply to protect your dog from lungworm, as well as other parasitic worms and fleas.

If you spot slugs and snails in your garden or local park, be extra vigilant when out walking your dog - Always pick up and safely dispose of your dog's faeces and consult your vet as soon as possible if your dog becomes unwell.

To find out more information on Lungworm and to find out if your area is a hotspot go to

If you have an interest in these pesky parasites, we have created a factsheet above, just click the link to download it!

The G.R Team

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