Eucoleus spp

From Dog
Bronchoalveolar lavage showing an extracellular E. aerophilus ovum with moderate, predominantly suppurative, inflammation on a mucoid background[1]

Eucoleus spp are a parasitic cardiopulmonary nematode of dogs found in most cosmopolitan countries.

Species which are pathogenic to dogs include:

  • Eucoleus aerophilus (syn. Capillaria aerophila) (pulmonary capillariasis)
  • Eucoleus boehmi (nasal capillariasis)

The life cycle of these parasites is not completely understood, and may develop to infective L3 larvae in the soil or involve a facultative intermediate host, presumably earthworms[2]. Adult E. aerophilus rside within the tracheopulmonary tree whereas E. boehmi reside within the epithelial lining of the nasal mucosa, turbinates, and sinuses[3].

Infections in dogs with E. aerophilia rarely cause more than a mildly pathological cough that can easily be dismissed as an allergic respiratory disease, similar to what is seen with Crenosoma vulpis. General respiratory distress, wheezing and sometimes sneezing is observed.

However, in the past decade, clinical cases of E. aerophilia in dogs have been reported[4] as well as zoonotic infection in humans[5].

In Europe, the nematode is commonly found in wildlife, but recently it has been identified in companion animals from Italy[6][7] and Portugal[8].

Adult E. aerophilus are rarely seen in clinical practice except accidentally under histopathological examination.

Adult E. boehmi can be isolated from the nasal passages using rhinoscopic nasal biopsy[9].

Diagnosis is based on coprological examination for eggs or larvae using the Baermann fecal flotation device[10].

A differential diagnosis would include other cardiopulmonary parasites such as Dirofilaria immitis, Crenosoma vulpis and Angiostrongylus vasorum.

Preventative therapy is effective with milbemycin oxime, selamectin and ivermectin.


  1. Burgess H et al (2008) Eucoleus aerophilus respiratory infection in a dog with Addison's disease. Can Vet J 49(4):389-392
  2. Bowman, DD (2009) Georgis' parasitology for veterinarians. 9th edn. Elsevier Saunders, Missouri. pp:226
  3. Schoning P et al (1993) Identification of a nasal nematode (Eucoleus boehmi) in greyhounds. Vet Res Commun 17(4):277-281
  4. Burgess H et al (2008) Eucoleus aerophilus respiratory infection in a dog with Addison's disease. Can Vet J 49:389–392
  5. Lalosević D et al (2008) Pulmonary capillariasis miming bronchial carcinoma. Am J Trop Med Hyg 78:14–16
  6. Di Cesare A et al (2010) Feline and canine cardio-pulmonary nematodes in central and southern Italy. Proceedings of the XXVI SoIPa Congress:22-25 June; Perugia, Italy. p:307
  7. Traversa D et al (2009) Infection by Eucoleus aerophilus in dogs and cats: is another extra-intestinal parasitic nematode of pets emerging in Italy? Res Vet Sci 87:270–272
  8. Madeira de Carvalho LM et al (2009) Proceedings of the Bayer Angiostrongylosis Forum, 19th Annual Congress of the European College of Veterinary Internal Medicine - Companion Animals: 9 September; Porto, Portugal. Bayer Animal Health GmbH, editor. Lungworms in domestic and wild carnivores in Portugal: rare parasites or rarely diagnosed? p:28
  9. Baan M et al (2011) Rhinoscopic diagnosis of Eucoleus boehmi infection in a dog. J Am Anim Hosp Assoc 47(1):60-63
  10. Campbell BG & Little MD (1991) Identification of the eggs of a nematode (Eucoleus boehmi) from the nasal mucosa of North American dogs. J Am Vet Med Assoc 198(9):1520-1523