Educational use only — not a substitute for professional medical or veterinary advice.

For educational purposes only. This page does not provide medical or veterinary advice, diagnosis, or treatment. Always consult a qualified healthcare or veterinary professional before making any health-related decisions.

Nematode (roundworm)Dog

Lungworm

Angiostrongylus vasorum / Crenosoma vulpis

Size: Visible to naked eye — adults 1–4 cm depending on species

Prevalence

Increasingly common in Europe, Canada, and parts of the United States; spreading to new geographic areas

Lungworm (Angiostrongylus vasorum, also called French heartworm) is a serious and potentially fatal parasite of dogs that lives in the pulmonary arteries and right side of the heart. Unlike heartworm, it is acquired by eating infected slugs, snails, or frogs — even accidentally by sniffing grass where slugs have passed. Young dogs are most at risk. Early diagnosis and treatment are critical.

Lifecycle

Dogs ingest infective larvae from slugs or snails (intermediate hosts). Larvae migrate through the gut wall to the lymph nodes, then travel via the bloodstream to the pulmonary arteries and heart. Adults mature and produce eggs that hatch into larvae, which are coughed up, swallowed, and passed in feces. Larvae are then ingested by slugs to complete the cycle.

Lungworm — Angiostrongylus vasorum / Crenosoma vulpis

LungwormAngiostrongylus vasorum / Crenosoma vulpis

Symptoms

Persistent cough and breathing difficulties
Exercise intolerance and lethargy
Unexplained bleeding — from wounds, nose, eyes, or gums
Clotting disorders (coagulopathy)
Weight loss and poor body condition
Neurological signs — seizures, ataxia (if larvae migrate to the brain)
Vomiting and diarrhea
Sudden death in severe cases

Pharmaceutical treatments

Evidence-based medications used by healthcare and veterinary professionals.

Reference only. Medication names, types, and notes are provided for general awareness. Dosage, suitability, and prescribing decisions must be made by a licensed physician or veterinarian.

Fenbendazole

Veterinary (Prescription)

Given daily for 21–28 days. Kills adult worms and larvae. Most commonly used treatment in the UK and Europe.

Milbemycin oxime (Milbemax)

Veterinary (Prescription)

Monthly preventive that also treats lungworm. Effective against larvae and adults.

Moxidectin + imidacloprid (Advocate/Advantage Multi)

Veterinary (Prescription)

Monthly spot-on treatment licensed for lungworm prevention and treatment in dogs.

Holistic & natural approaches

Traditional, herbal, and integrative approaches for general awareness.

Not a substitute for medical treatment. Natural remedies listed here have not been evaluated by the FDA or equivalent regulatory bodies. Do not use these in place of prescribed treatment. Always consult a qualified healthcare or veterinary professional first.

Dietary diatomaceous earth (food grade)

Some pet owners use food-grade DE as a supportive measure. Evidence is anecdotal. Not a substitute for veterinary treatment in confirmed lungworm infection.

Immune-supportive nutrition

High-quality protein and omega-3 fatty acids may support recovery. Discuss with a veterinarian before making dietary changes during treatment.

Prevention

Use monthly prescription lungworm preventives in endemic areas
Prevent dogs from eating slugs, snails, frogs, or grass where slugs have been
Remove slugs and snails from garden areas
Do not leave water bowls or food outside overnight (attracts slugs)
Regular fecal testing (Baermann technique) in high-risk areas
Consult your vet about year-round prevention if you live in an endemic region

Zoonotic risk — low or none

Angiostrongylus vasorum does not infect humans. A related species, Angiostrongylus cantonensis (rat lungworm), can cause eosinophilic meningitis in humans but is a distinct parasite with a different lifecycle.

This information is for educational purposes only and is not a substitute for professional medical or veterinary advice. If you suspect a parasitic infection, consult a qualified healthcare or veterinary professional.