Lungworm in dogs

Lungworm in dogs is a serious and potentially fatal disease. Dogs get infected by eating slugs or snails carrying larvae of the parasite Angiostrongylus. Common symptoms include coughing, breathing problems and unexplained bruising. Young, curious dogs and puppies are most at risk.

87% of UK vets have seen cases of lungworm in dogs, with 30% reporting deaths. The numbers and spread of cases are increasing every year. Symptoms of lungworm are varied and early stages are easily-mistaken for other illnesses. The best way to protect your dog against lungworm is with regular preventive care, using a vet-prescribed wormer. Always seek prompt veterinary advice if your dog develops a new and persistent cough or unexplained bruising.

Overview

What is Lungworm in dogs?

Angiostrongylus vasorum is the most common lungworm in the UK . Adult lungworms live inside your dog’s heart and the major blood vessels going to their lungs. You won’t see evidence of these worms until your dog starts to cough.

Snails and slugs carrying Angiostrongylus larvae are found all across the UK, but more so in certain regions.
When a dog or fox eats a snail or slug, the larvae migrate from the intestines through the liver and into the bloodstream.
When larvae reach the heart, they mature into adults.
Adult worms breed in the heart. Their eggs hatch into larvae which enter the airways.
From the lungs, the larvae are coughed up, swallowed, and pass out of the body in poo.
There the larvae can infect passing slugs and snails.

How do dogs get lungworm?

By eating slugs or snails infected with Angiostrongylus larvae
Eating grass with slugs on it or drinking from puddles containing lungworm larvae
Licking slime trails: the sticky slimy substance produced by slugs
Eating food or drinking from bowls contaminated with snail slime
Playing with and licking toys which have been left outside overnight, exposed to slugs

What time of year has the most risk?

The risk is present all year round. However:

Slugs hatch in February and breed August-September, then die off
Slugs are most active in mild damp conditions
Dogs pick up the parasite in summer and autumn, when slugs are abundant and larvae mature.
Vets diagnose most coughing lungworm cases in winter and spring

Climate change is bringing milder, damper weather, favouring slug activity and year-round breeding.

Why does Lungworm make dogs sick?

Migrating larvae damage the tissues and blood vessels they pass through as they make their way towards the heart. This triggers inflammation.
Adult worms damage the heart and blood vessel walls.
Worms in blood vessels interfere with circulation of blood to the lungs. Poor blood circulation in the lungs means less oxygen gets into the body.
Your dog’s body fights the invading larvae and adult worms. Sometimes this immune reaction is so severe, it worsens the inflammation.
Severe immune reactions can result in problems with blood clotting, uncontrolled bleeding and organ failure.

Are there other types of lungworm in the UK?

Other lungworms are very rare in the UK but include:

Oslerus osleri

Lives in the windpipe (trachea) and larger airways
Transmitted from bitches to pups in saliva during grooming
Usually found in dogs under 2 years old

Crenosoma vulpis or Fox Lungworm

Lives in windpipe and airways
Infection from eating slugs or snails or a creature which has eaten these

Symptoms

Symptoms of Lungworm infection in dogs

Symptoms of lungworm in dogs range from mild to life-threatening. The severity and type of symptoms depends on:

The number of worms present
What parts of the body the larvae reach
The intensity of your dog’s immune response.

Symptoms include:

Coughing in about 70% of cases; lasting weeks to months
Breathing difficulties: fast, laboured, heavy or noisy breathing in 23% of cases
Unexplained or prolonged bleeding and unexpected bruising in around 15% of cases
Lethargy, low energy and weakness, in 15% of cases
Not eating in 14% of cases
Weight loss in 11% of cases
Seizures, resulting from bleeding in the brain
Collapse and shock

Risk

Which dogs are most likely to get lungworm?

Worming

Dogs who don’t get a regular prescription wormer effective against Angiostrongylus

Geographical Location – Where you live

Slugs infected with Angiostrongylus larvae are most common in certain parts of the UK
Large numbers of infected foxes live in the South East of the UK
You can check the prevalence where you live on the Elanco lungworm map

Age

Young dogs, more likely to be curious about slugs and snails
Dogs under 2 years old are 4 times more likely to get Angiostrongylus lungworm

Breed

Although any dog can get lungworm, but purebred dogs are reported to be 20 times more likely to develop lungworm than cross-breeds
Cocker Spaniels and Cavalier King Charles Spaniels seem to be more susceptible
Staffordshire Bull Terriers seem less at-risk

Lifestyle: The average UK garden has 20000 slugs, increasing the risks for:

Dogs who spend a lot of unsupervised time in their garden
Dogs whose toys are left out in the garden overnight
Dogs who are fed outside

Are infected dogs a risk to other pets and people?

Infected dogs shed Angiostrongylus larvae into the environment. Where slugs are also present, this increases infections risks for other dogs in the household/neighbourhood
Humans don’t catch Angiostrongylus lungworm from dogs

Diagnosis

How do vets diagnose Lungworm in dogs?

Lungworm in dogs can be difficult to recognise and diagnose. There’s a wide range of symptoms. These symptoms can also be caused by other common illnesses.

Diagnosis is based on:

Symptoms and known risks
Blood tests: The IDEXX Angio Detect Test gives results in minutes
Faecal tests: looking for Angiostrongylus eggs or larvae
Chest x-rays
Bronchoscopy: passing a special camera along the windpipe to look at the airways

Vet treatment

How do Vets treat Lungworm in dogs?

Treatment for lungworm in dogs depends on the symptoms and their severity. If your dog is diagnosed and treated early, their outlook is likely to be good. Dogs who develop severe symptoms, such as breathing difficulties and seizures, have a poor outlook and sadly, may not survive.

Mild infections: coughing

Medicine to kill the parasite: granules, liquid, paste or tablets
Careful monitoring: killing lots of worms at once can trigger a severe allergic reaction and collapse

Severe infections: coughing, anaemia, collapse

Emergency hospital treatment:
Oxygen: when lungworms cause severe lung damage
Fluid therapy: Life-saving fluids given directly into a vein in your dog’s leg
Blood transfusion: to replace your dog’s red blood cells and help their blood to clot
Other medications: depending on your dog’s symptoms. For example, anti-seizure medication

Home treatment

How to look after a dog with Lungworm at home

There are no home remedies for Lungworm. Affected dogs need prompt veterinary care and prescription medicine.

If you see your dog come into contact with a slug or snail or licking slug slime:

Wash their mouth out thoroughly
Clean their teeth
Contact your vet to get a prescription wormer effective against Angiostrongylus

After seeing a vet:

Give all prescribed medicines at the correct time and dose
Complete the course of treatment
Keep recovering dogs calm and let them rest
Keep your dog cool in a well-ventilated room

Prevention

How to prevent Lungworm in dogs

Preventing lungworm is much easier than treating it. Across-the-counter wormers won’t treat Lungworm.

Use regular, monthly preventive treatments: ask your vet for a suitable prescription wormer
Regular treatment prevents further spreading of the parasite in the environment
Don’t feed your dog outside
Avoid leaving food bowls and toys outside, and wash them daily to remove any slug slime
Try to prevent your dog from eating snails or slugs in your garden or on walks
Walk your dog on the lead in the mornings and evenings and in damp weather, when they’tre more likely to come across slugs and snails

When to worry