Rev 10/22/2025
Chromadorea
Rhabditia
Rhabditida
Metastrongyloidea
Filaroididae
Type species of the genus
Synonyms
Filaroides osleri Cobbold, 1979
Species named in honor Sir William Osler who recovered it from dogs in 1877 in Montreal. Canada.
Males:
Female:
Ref: Marchiondo (2020).
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Filaroides osleri is a worldwide lungworm of domestic and wild dogs. Reported from coyotes (Canis latrans), domestic dogs (Canis lupus familiaris) and gray wolves (Canis lupus) in North America. Fox (Lycalopex vetulus) in Brazil
Filaroid parasites of the mucosa of trachea, bronchi and other components of the respiratory tract of canids.
Larvae embed in fibrous nodules within the epithelium of the trachea at the region of bifurcation and in adjacent bronchi. Adult nematodes are located in nodules in the submucosa of the trachea and bronchi of the host. Submucosal nodules of adult nematodes are surrounded by fibrosis and lymphoplasmacytic inflammation (Verocai et al., 2013)..
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Life cycle direct, no intermediate host
Eggs deposited in the liungs of the definitive host hatch immediately to the L1 (237-267 um long).The L1 has a kinked tail but no accessory spine.
Eggs and larvae are coughed up and swallowed before being passes in the feces or regurgitated.
Transmission in domestic dogs occurs by maternal grooming of bitches to pups by L1 contaminated saliva while regurgitative feeding of pups by parents is a major transmission route in free ranging canids. Autoinfection is possible.
The L1 penetrate the intestinal wall, travel to the heart by way of the lymphatic or hepatic circulation and finally to the lungs via the pulmonary arteries.
Larvae develop to adults in the respiratory tract forming tracheobronchial nodules under the luminal epithelium.
The prepatent period is 2 weeks (Marchiondo, 2020)
Ecophysiological Parameters:
Infected dogs were disinfected by repeatd treatments of 5 days application oof anthelminthics.
Sanitation of fecal material.
Marchiondo, A.A. 2020. Nematoda, Metastrongyloidea. Chapter 2 in Marchiondo, Cruthers and Fourie (eds) Parasiticide Screening Vol 2. Academic Press
Verocai, G.O., Schock, D.M., Lejeune, M., Warren, A.L., Duignan, P.J., Kutz, S.J. 2013. Oslerus osleri (Metastrongyloidea; Filaroididae) in Gray Wolves (Canis lupus) from Banff National Park, Alberta, Canada. J. Wildlife Diseases 49:422-426. https://doi.org/10.7589/2012-07-186