What is Lungworm
A lungworm is a type of parasitic worm that can infect dogs. Unlike other intestinal worms such as tapeworms and roundworms, adult lungworm travels around a dog's body and can damage their lungs and other major organs.
Lungworm infection in dogs occurs when they ingest larvae from slugs, snails, or their slime. Once inside the dog, the larvae mature, migrate to the lungs, and reproduce. The new larvae are coughed up, swallowed, and passed out in faeces, continuing the cycle.
Written by Dr. Mariella Roberts, Veterinary Surgeon, Animal Trust Vets CIC | Published April 2025 | Review date April 2027 | This advice is for UK pets only and is not a replacement for seeing a vet
Symptoms of lungworm disease
Symptoms 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
General sickness
Circling
Stomach and back pain
Eating less
Vomiting
Diarrhoea
Behaviour changes (depression, being tired)
Seizures
When to contact your vet
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 early.
Diagnosis
Diagnosing lungworm can be tricky; your vet will carry out a number of diagnostic tests, such as taking blood and faeces samples to see if any eggs or larvae are present. They may also conduct a chest x-ray or insert a tiny camera into your dog’s windpipe to find evidence of the parasite.
Treatment
The goals of the treatment are to eliminate the parasite and to control any symptoms caused by inflammation.
The parasites can be killed with specific anti-parasitic drugs depending on the type of lungworm. Different medications are available.
Depending on the severity of the dog’s infection, the medication will be prescribed for several weeks to several months. When the dog’s symptoms are moderate, your vet may prescribe medication to alleviate inflammation. In the rare case where the dog has severe respiratory distress, hospitalisation for oxygen therapy or other supportive treatments may be necessary.
Prevention
The best way to approach lungworm is to prevent your dog from catching it in the first place. There are several lungworm treatments that are highly effective at preventing your dog from catching lungworm, and there are a few other things you can do that will also help keep your dog safe:
Don’t miss regular deworming treatments
Remove toys and water bowls from the garden where slugs roam
Be careful when walking your dog if you spot any snails
Outlook
Once diagnosed and treated, most dogs will recover fully from lungworm. But the earlier the treatment, the better the outlook. If the condition is left untreated, it can be fatal.