What Is Lungworm?
Lungworm is a general name for several parasitic worms that live in the airways, lung tissue or the blood vessels of the lungs and heart. They can infect both dogs and cats. Most pets catch them by eating slugs, snails, or animals such as frogs, rodents and birds that carry the larvae.
Lungworm is less common in the US than intestinal worms, but it is easy to miss because the signs look like allergies, asthma or kennel cough.
Why it matters
One type, Angiostrongylus vasorum (French heartworm), can interfere with blood clotting and cause serious bleeding. It is well established in parts of Europe and has been found in Newfoundland, Canada, so travel history matters.
Common Types
- Aelurostrongylus abstrusus (cats): the main feline lungworm, picked up from snails, slugs or prey. It is a known look-alike for feline asthma.
- Oslerus osleri (dogs): forms nodules in the windpipe and causes a chronic cough, often in young dogs.
- Crenosoma vulpis (dogs): the fox lungworm, spread by snails and slugs, and found in the northeastern US and Canada.
- Eucoleus (Capillaria) species: live in the airways or nasal passages of dogs and cats.
- Angiostrongylus vasorum (dogs): lives in the pulmonary arteries and heart and can cause bleeding problems.
Signs Owners Notice
- A persistent cough or wheezing that does not clear up
- Faster or labored breathing and tiring easily on walks
- Weight loss or poor appetite
- With Angiostrongylus: nosebleeds, bruising, bleeding that will not stop, or collapse
- Some infected pets show no signs at all
Diagnosis
Lungworm larvae are found in feces using a special test (the Baermann technique), which works better than a routine fecal float. Your vet may also use chest X-rays, an airway wash or bronchoscopy, and blood tests that detect Angiostrongylus antigen. Several samples over consecutive days may be needed because larvae are shed on and off.
Treatment and Outlook
- Dewormers: fenbendazole, moxidectin and certain other antiparasitic drugs are used depending on the species.
- Supportive care: anti-inflammatory medication, oxygen, or rest for pets with breathing trouble.
- Follow-up testing: a repeat fecal test confirms the worms are gone.
Most pets recover fully when lungworm is caught early. Severe Angiostrongylus cases with bleeding are more serious and may need hospital care.
Practical Tips for US Pet Owners
- Discourage dogs from eating slugs and snails, and pick up toys and bowls left outdoors overnight.
- Ask your vet whether your monthly parasite preventive also covers lungworm; some moxidectin products do.
- Follow a regular deworming schedule for dogs and see deworming cats for hunting cats.
- Find a nearby practice through veterinary clinic listings.
When to see a vet
Book a visit for any cough lasting more than a week or two. Go urgently if your pet has trouble breathing, unexplained bleeding or bruising, or collapses. See kennel cough for a common look-alike.
Key Takeaways
- Lungworms live in the lungs or lung blood vessels of dogs and cats.
- Slugs, snails and prey animals are the main sources of infection.
- A special fecal test finds most cases, and dewormers usually clear them.
FAQ
Can humans catch lungworm from pets?
The pet lungworms described here are not considered a risk to people through normal contact. Good hygiene after handling feces is still wise.
Is lungworm the same as heartworm?
No. Heartworm is spread by mosquitoes. Lungworms are spread mainly by slugs, snails and prey, although Angiostrongylus is nicknamed French heartworm.
Does a normal fecal test catch lungworm?
Not reliably. Ask for a Baermann test if your vet suspects lungworm.