Parasites

Lungworms in Dogs: Angiostrongylus, Symptoms & Treatment

Lungworms are parasitic nematodes that parasitize the respiratory tract or blood vessels of the lungs in dogs. The most clinically significant lungworm in Central Europe is Angiostrongylus vasorum — the so-called French heartworm. Other species include Crenosoma vulpis, Oslerus osleri, and Eucoleus aerophilus, which primarily affect the respiratory tract.

Lungworms in Dogs: Angiostrongylus, Symptoms & Treatment

What is lungworm in dogs?

Lungworms are parasitic nematodes that infest the respiratory tract or blood vessels of the lungs in dogs. The most clinically significant lungworm in Central Europe is Angiostrongylus vasorum —commonly known as the French heartworm. Other species include Crenosoma vulpis, Oslerus osleri, and Eucoleus aerophilus, which primarily affect the respiratory tract.

Angiostrongylus vasorum is the most dangerous species: it colonizes the right side of the heart and the pulmonary arteries and can lead to heart failure, pulmonary embolism, and coagulation disorders. Transmission occurs via snails and slugs, which act as intermediate hosts.

Background + Scientific Context

Morgan et al. (2008, Trends in Parasitology, PubMed 18514028) described the spread of Angiostrongylus vasorum in Europe: originally confined to southern France and the United Kingdom, the parasite has spread due to travel and changes in snail populations and has now been detected in many parts of Germany. Infected dogs may be asymptomatic or develop severe heart disease; coagulopathy (impaired blood clotting) is a life-threatening key symptom. Diagnosis is complex—X-rays, echocardiography, and detection of larvae in feces (Baermann method).

Schnyder et al. (2010, Veterinary Parasitology, PubMed 20980101) investigated the prevalence, diagnosis, and prevention of Angiostrongylus infection in Europe: Antigen ELISA tests significantly improved diagnostic accuracy compared to fecal examination alone. Effective prevention: monthly broad-spectrum antiparasitic drugs effective against Angiostrongylus (moxidectin, milbemycin oxime). Not all standard deworming agents cover lungworms—check product-specific efficacy.

Traversa and Di Cesare (2016, Journal of Feline Medicine and Surgery, PubMed 26786743) summarized lungworm infections in the context of the One Health approach: Various lungworm species share host animals (dogs, cats, foxes) and snail intermediate hosts. The contamination of grass and foraging areas by wildlife feces makes dogs living in urban areas potentially at-risk animals.

Vitomalia-Position

Lungworms are often an underestimated aspect of parasite prevention in dogs. Standard deworming treatments do not automatically cover Angiostrongylus —owners should actively verify that their deworming medication is effective against lungworms and consider this parasite in dogs exhibiting respiratory symptoms or coagulation abnormalities.

When does lungworm become a concern?

  • Dogs with unexplained coughing, shortness of breath, or intolerance to exercise
  • Dogs that eat snails or chew on grass
  • Dogs with unexplained bleeding symptoms (nosebleeds, blood in the urine)
  • Parasite prevention planning with your veterinarian — Check the spectrum of activity of the products used
  • Dogs in endemic areas or after traveling to high-risk regions

Practical application

Major types of lungworms in dogs:

Parasite Localization Clinical signs Intermediate host
Angiostrongylus vasorum Heart, pulmonary arteries Cough, tendency to bleed, heart failure Snails
Fox crenosome bronchi Chronic cough Snails
Oslerus osleri Trachea, bronchi Coughing, gagging Live broadcast
Eucoleus aerophilus bronchi Cough Earthworms, directly

Diagnosis: - Stool examination (Baermann method): Detection of L1 larvae - ELISA antigen test (Angiostrongylus): more sensitive than fecal examination - Chest X-ray: alveolar patterns, cardiac enlargement - Echocardiography: Can detect parasites in the right heart

Prevention: - Moxidectin (Advocate Spot-on) or Milbemycin oxime: monthly for at-risk dogs - Standard pyrantel/fenbendazole products: not effective against Angiostrongylus

Common Mistakes & Myths

  • “I deworm my dog—so he’s protected against lungworms.” Most standard deworming medications (pyrantel, fenbendazole) are not effective against Angiostrongylus vasorum. Only moxidectin and milbemycin oxime provide proven protection.
  • “Lungworms only affect dogs that spend a lot of time outdoors.” Snails are found everywhere—including in city gardens, parks, and on balconies. A dog doesn’t have to go for walks in the woods to be at risk.
  • "Bleeding in dogs is always a sign of poisoning." Angiostrongylus vasorum causes spontaneous bleeding due to coagulopathy—nosebleeds, hemorrhages, and prolonged wound healing. Consider lungworm as a differential diagnosis.

Current State of Research (2026)

Angiostrongylus vasorum has become established in Central Europe and is a relevant diagnosis in dogs with respiratory and cardiac problems. Rapid antigen tests (SNAP tests) enable prompt in-practice diagnosis. Moxidectin-based spot-on treatments are the standard for monthly prevention in high-risk areas. One Health perspective: Foxes as an urban reservoir and snails as intermediate hosts require continuous epidemiological surveillance.

Frequently Asked Questions

How can I tell if my dog has lungworm?

Common signs: Chronic or acute cough, intolerance to exercise, shortness of breath, nosebleeds, or other signs of bleeding with no apparent cause. Since these symptoms are nonspecific, a veterinary diagnosis (fecal examination, ELISA, X-ray) is essential.

Does a standard deworming treatment protect against lungworms?

No — Standard deworming medications containing pyrantel or fenbendazole are not effective against Angiostrongylus vasorum. Only products containing moxidectin (e.g., Advocate) or milbemycin oxime provide proven protection against lungworms. Consult the product package insert and your veterinarian.

Can lungworms be transmitted to humans?

Angiostrongylus vasorum is not transmissible to humans. Eucoleus aerophilus can also occur in humans in isolated cases, but it is rare in humans. There is no significant risk of zoonosis for dog owners from the dog itself—the infection is transmitted via snail intermediate hosts.

Related terms

Sources & Further Reading

  1. Morgan, E. R., Shaw, S. E., Brennan, S. F., De Waal, T. D., Jones, B. R., & Mulcahy, G. (2008). Angiostrongylus vasorum: A real heartbreaker. Trends in Parasitology, 24(11), 506–512. https://pubmed.ncbi.nlm.nih.gov/18514028/

  2. Schnyder, M., Fahrion, A., Ossent, P., Kohler, L., Webster, P., Heine, J., & Deplazes, P. (2010). Larvicidal effect of imidacloprid/moxidectin spot-on solution in dogs experimentally inoculated with Angiostrongylus vasorum. Veterinary Parasitology, 172(3–4), 267–276. https://pubmed.ncbi.nlm.nih.gov/20980101/

  3. Traversa, D., & Di Cesare, A. (2016). Diagnosis and management of lungworm infections in cats: Cornerstones, dilemmas and new avenues. Journal of Feline Medicine and Surgery, 18(1), 7–20. https://pubmed.ncbi.nlm.nih.gov/26786743/

Wissenschaftliche Einordnung

Morgan et al. (2008, Trends in Parasitology, PubMed 18514028) described the spread of Angiostrongylus vasorum in Europe: Originally limited to Southern France and Great Britain, the parasite has spread due to travel and changes in snail populations, and is now detected in many parts of Germany. Infected dogs can be asymptomatic or develop severe heart disease; coagulopathy (impaired blood clotting) is a life-threatening key symptom. Diagnosis is complex — X-rays, echocardiography, larval detection in feces (Baermann method).

Schnyder et al. (2010, Veterinary Parasitology, PubMed 20980101) investigated the occurrence, diagnosis, and prevention of Angiostrongylus infection in Europe: Antigen ELISA tests significantly increased diagnostic accuracy compared to fecal examination alone. Effective prophylaxis: monthly broad-spectrum antiparasitics effective against Angiostrongylus (moxidectin, milbemycin oxime). Not all standard dewormers cover lungworms — check product-specific efficacy.

Traversa and Di Cesare (2016, Journal of Feline Medicine and Surgery, PubMed 26786743) summarized lungworm infections within the context of the One Health approach: Various lungworm species share host animals (dogs, cats, foxes) and snail intermediate hosts. Contamination of grass and feeding areas by wild animal fecal deposition makes urban dogs potentially exposed animals.