Dictyocaulus arnfieldi

  

Contents

  

Rev 10/21/2025

Lungworm of Equids Classification Biology and Ecology
Morphology and Anatomy Life Cycle
Return to Dictyocaulus Menu   Ecosystem Functions and Services
Distribution Management
Return to Dictyocaulidae Menu Feeding  References
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Classification:

Chromadorea

  Rhabditia

    Rhabditida

      Metastrongyloidea

       Dictyocaulidae

       
Dictyocaulus arnfieldi Cobbold, 1884

 

Synonyms
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Morphology and Anatomy:

 

   
   





Males:  

  • 25-43 mm long, 133-259 um wide

  • Bursa with branches of the dorsal ray bilobed distally and the ventroventral raysmuch shorter than the lateroventral rays.

  • Spicules slightly bent, 199-250 um long
  • Gubernaculum ovoid, 40-57 um long

 

Female:  

  • Length 43-68 mm, 400-500 um wide
  • Tail short, bent, 280-450 um long withe blunt tipg
  • Vulva anterior to mid body.
  • Eggs that are ellipsoid (80-100 x 55-60 um) containing fully developed L1 (420-480 um long 15-17 um wide) with pointed tail.

Ref: Snyder et al., 2020

 

 

Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

 
 
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Distribution:

Worldwide, especially temperate climates with high rainfall (Snyder et al., 2020).

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Feeding:

 Found in the air passages of the lungs. Occurs in the the trachea and bronchi, of donkeys and horses.

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Biology and Ecology:

 

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Life Cycle:

Unlike other Metastrongyloidea, Dictyocaulus spp do not require an intermediate host, the lifecycle is direct. That leads Snyder et al (2020) to suggest classification in the Trichostrongyloidea would be more appropriate.

Dictyocaulus arnfieldi lives in the lumen of the bronchial tree of its definivive host.  The lifecycle is similar to thet of D. viviparus.

Females produce eggs in the bronchii; newly hatched L1 larvae migrate up the trachea, are swallowed and passed out in the feces. They develop to the  infective L3 develop in about 5 days in the environment and migrate or are projected (from the sporangium of the fungus, Pilobolus) to herbage away from the fecal pat.

The L3 are ingested by the definitive host during grazing and penetrate the intestinal mucosa and migrate to the mesenteric lymph nodes. In the lymph nodes they  molt to the L4 and travel  to the lungs via the lymph and thoracic duct. The L4 break out of the capillaries into the alveoli in about a week after infection and molt in the bronchioles to young adults that move up the bronchii and mature.

The prepatent period is about 2-4 months (Snyder et al., 2020)

 
   

Ecophysiological Parameters:

For Ecophysiological Parameters for this species, click If species level data are not available, click for genus level parameters
 
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Ecosystem Functions and Services:

 

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Management:

Anthelmithics, ivermectin

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References:

Anderson, R.C. 2009. Keys to the nematode parasites of vertebrates: archival volume. https://doi.org/10.1079/9781845935726.0178

Snyder, D.E., Marchiondo, A.A. Cruthers, L.R. 2020. Nematoda, Trichostrongyloidea. Chapter 2 in Marchiondo, Cruthers and Fourie (eds) Parasiticide Screening Vol 2. Academic Press

 

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Copyright © 1999 by Howard Ferris.
Revised: October 21, 2025.