Lungworm in Dogs: Symptoms, Treatment and Prevention

Lungworm in dogs is no longer a rare countryside problem—UK vets now see cases from Cornwall to the Scottish Borders. This guide explains how the worm’s life cycle works, how dogs catch lungworm, how common it is, and the early signs to spot—so you can protect your dog, your pocket and your peace of mind.

What Is Lungworm?

Lungworms are a type of parasite (Angiostrongylus) that affects dogs and foxes, but not humans. Once in a dog's body, the tiny lungworm larvae live in the major blood vessels of their heart and lungs, causing a range of potentially serious health problems.

How Do Dogs Catch Lungworm?

Dogs catch lungworm by swallowing tiny lungworm larvae carried by infected slugs and snails. This can happen while sniffing or licking wet grass, drinking from puddles, or chewing dog toys left in the garden. Even slime trails from these molluscs can spread the parasite. According to Blue Cross, most dogs don't need to eat a slug—just licking one is enough to start a lungworm infection.

Once inside the dog’s body, the larvae travel to the heart and lungs, where they mature into adult lungworms and begin to lay eggs. These pass out in the dog's faeces, which then infect other slugs and restart the life cycle.

To reduce the risk of catching lungworm, bring in water bowls and toys at night, clean up poo quickly, and use monthly worming treatments that target lungworm. Being extra vigilant after rain is key, as that's when slugs and snails are most active.

How Common Is Lungworm?

Lungworm in dogs is now endemic across much of the UK. Elanco’s interactive Lungworm Map lists more than 2,200 reported lungworm infection cases, with outbreaks recorded from Cornwall up to central Scotland. A University of Bristol study found lungworm larvae in 16 % of symptomatic dogs and 2 % of apparently healthy pets in south-west Britain, proving that dogs catch lungworm even when no signs show. Because infected slugs and snails thrive year-round, most dogs need monthly worming treatments and good garden hygiene to stay safe.

Symptoms of Lungworm in Dogs

Lungworm in dogs can be hard to spot at first. Early signs are often mild but can get serious quickly. Common symptoms include:

• A soft, persistent cough

• Tiredness or low energy

• Bruising or bleeding (nose, gums, or in urine)

• Poor appetite, vomiting, or weight loss

• Seizures or unusual behaviour in severe cases

lungworm cough usually dry and quiet—like a soft “honk” or wheeze—and may get worse after play or rest.

Because the parasite damages the lungs, heart, and blood vessels, these signs can appear slowly or all at once. If your dog shows any of these symptoms, contact your vet immediately. Diagnosing lungworm early means faster treatment and a better chance of full recovery.

PDSA and Blue Cross both warn that left untreated, lungworm can cause life-threatening bleeding or organ failure—even in young, healthy dogs.

When to Call Your Vet

Breathing problems, constant cough, or sudden bruises are red flags for lungworm in dogs. If your dog coughs after play, has nosebleeds, or seems weak, phone the vet immediately. Severe lungworm infections can kill within days because adult worms damage the heart and blood vessels. PDSA warns owners never to “wait and see” once these clinical signs appear. Most dogs recover if they are treated early, so act fast and tell the clinic you suspect a lungworm infection.

Diagnosing Lungworm in Dogs

Vets use three main tests to diagnose lungworm:

• Faecal Baermann test – looks for live lungworm larvae in the dog's faeces.

• Blood or PCR test – spots hidden worms before symptoms worsen.

• Chest X-ray/scan – shows adult lungworms near the heart.

The Animal & Plant Health Agency lists the Baermann as the gold standard for UK clinics. Catching the worms early keeps costs low and stops them moving into the spinal cord or lungs.

Treatment Lungworm in Dogs

The goal is simple — treat lungworm fast and stop new worms from hatching. UK vets follow three clear steps:

Kill the worms

• Licensed lungworm treatments use macrocyclic lactones.

• Moxidectin + imidacloprid (spot-on) needs one dose; a repeat may be given after four weeks.

• Milbemycin oxime (tablet) is often given weekly for four weeks in severe lungworm infections.

• Fenbendazole paste or granules can be used when young pups, pregnant bitches or sensitive dogs cannot take other drugs.
  These medicines wipe out both larvae and adult lungworms, ending the lungworm infection quickly.

Support the patient

Lungworm damages blood vessels, so some dogs need oxygen, pain relief, fluids, or a plasma transfusion to control bleeding. The Royal Veterinary College reports clotting troubles in around 20 % of hospital cases.

Confirm the cure

A new Baermann or PCR test on the dog’s faeces 6–8 weeks later checks no lungworm larvae remain. Caught early, most dogs bounce back within days; late or left-untreated cases may need months of rest. Both PDSA and Blue Cross remind owners that monthly worming treatments cost far less than emergency care and are the best form of lungworm prevention.

Cost

Treating lungworm can cost from £80 for basic medicine to £600 or more if a dog needs hospital care, according to PDSA’s cost cost guidance. Pet-insurance policies that cover “parasitic worm” conditions can soften the blow, but owners should still plan for an excess payment. Buying prescription wormers online may look cheaper, yet vets warn that a mistimed or incorrect dose can lead to more expensive complications. Comparing valid prescription prices through reputable pharmacies like Vetscriptions can save up to 40 %, but only if you follow your vet’s dosing plan. Prevention remains the cheapest route.

Preventing Lungworm in Dogs

A strong lungworm prevention plan stops the parasite long before it harms your dog’s body. UK charities list four habits that make the biggest difference:

1. Monthly worming treatments that name lungworm — drugs such as moxidectin + imidacloprid or milbemycin wipe out hidden larvae before they mature into adult lungworms. PDSA recommends year-round cover for most dogs, even those that rarely leave the garden.

2. Slug & snail control — bring in dog toys, chews and outdoor water bowls each night; clear away fallen fruit, and keep lawns short so you can spot slugs easily. Blue Cross notes that slime trails on toys are a key route for dogs to catch lungworm.

3. Fast poo pick-up — larvae pass in the dog’s faeces, infecting more molluscs and restarting the life cycle. Daily clean-ups break that chain.

4. Extra vigilance after rain — slug activity soars in damp weather; shorten walks through heavy undergrowth and stop pets from licking puddles.

These simple steps, plus regular vet check-ups, keep severe lungworm infections rare and far cheaper to treat.

Ongoing Care

Treatment kills the worms, but healing continues after the last tablet. Vets advise a retest of the dog’s faeces or a PCR sample six to eight weeks later to confirm no lungworm larvae remain. The Royal Veterinary College reports that bleeding disorders or breathing problems can linger for months because the parasitic worm damages small blood vessels and lung tissue.

Most dogs bounce back quickly if the infection is caught early, yet owners should:

• Keep monthly wormers going for life—immunity is weak, so dogs can be reinfected by eating slugs again.

• Watch for returning common symptoms such as cough, tiredness or appetite loss; call the vet immediately if they appear.

• Re-introduce exercise slowly; strenuous play too soon may trigger coughing or breathing difficulties.

• Maintain slug-proof habits at home to protect other pets in local dog communities.

With these measures, even dogs that suffered severe cases can enjoy a full, active life—and owners gain peace of mind that the lungworm infection won’t come back.

Can Humans Get Lungworm?

The lungworm species that infect dogs—Angiostrongylus vasorum—does not infect humans, notes the APHA disease information sheet. That means owners can handle their pets without fear. Basic hygiene, like washing hands after gardening and disposing of dog’s faeces, still protects public health from other parasites and bacteria.

Can My Dog Pass the Infection on to Other Pets?

Pets do not catch the worm directly from each other. Instead, larvae leave an infected dog in poo, infect slugs, and then infect new dogs. Picking up droppings and controlling slugs stops the spread in dog communities.

Can My Dog Develop This Problem Again?

Yes. Once the larvae mature, they lay eggs for months. Stop monthly cover and your dog can be reinfected by eating slugs or licking wet grass. Blue Cross stresses lifelong prevention for every dog, even seniors and house-pets

FAQs

How do I tell if my dog has lungworm?

Look for common symptoms: persistent cough, bruising, nosebleeds, tiredness, appetite vomiting, or seizures. If you notice any, see your vet immediately for tests.

What kills lungworm in dogs?

Vet-prescribed wormers containing moxidectin or milbemycin kill lungworm larvae and adults. Over-the-counter intestinal wormers rarely cover this parasite.

What does lungworm cough sound like?

Owners often describe it as a soft, dry “honking” cough that lingers for days and may worsen after play. Breathing problems or gagging during rest are red flags for severe cases.

Conclusion

Lungworm in dogs is serious—but it’s also preventable. With monthly worming treatments, good garden hygiene, and early action on warning signs, you can protect your dog from this dangerous parasitic worm. Stay alert after rain, clean up your dog’s faeces, and speak to your vet about the right prevention plan. Caught early, lungworm is treatable—and your dog can make a full recovery.