Stephanurus dentatus

Contents

Rev 08/07/2025

Kidney Worm Classification Biology and Ecology
Morphology and Anatomy Life Cycle
Return to Stephanurus Menu Ecosystem Functions and Services
Distribution Management
Return to Syngamidae Menu Feeding  References
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 Classification

Phylum:  Nematoda
Class:    Chromadorea
Order:    Rhabditida 

Superfamily:  Strongyloidea

Family:  Syngamidae

Stephanurinae

 

Stephanurus dentatus Diesing, 1939

 

Type species of the genus.

 

Recent phylogenetic analyses susggest that S. dentatus is closer to the family Chabertiidae than to the family Syngamidae (Deng et al., 2021).

 

Synonyms:

Sclerostoma pinguicola Verrill, 1870

Strongylus dentatus Dean, 1874

Stephanurus nattereri Cobbold, 1879

Strongylus (Sclerostoma) pinguicola (Verrill, 1870) Magallaes, 1894

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Morphology and Anatomy:

 

Females

Males:

Ref: Daubney, 1923

 
Stephanurus dentatus: Left: Head, lateral view; Right: female tail
smp = submedian head papilla; lp = lateral head papilla; gc = genital cone; int - intestins; cp = cuticular tail process; an = anus
Drawings from Daubney, 1923
 

 

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


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Distribution:

Mainly in tropical and subtropical environments.

 

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Economic Importance:

Infected pigs grow more slowly; economic costs of lower rates and magnitude of weight gain.. A significant parasite of wild and domestic swine in tropical and subtropical regions.

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Hosts:

Wild and domestic swine.

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Feeding:

Parasite of the peritoneal fat, the pelvis of the kidney, the walls of ureters and the liver of both domestic and wild swine (Singh and Kaushal, 1995). Adults are large nematodes and food consumpion is considerable.

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Life Cycle:

Stepanurus.dentatus has a direct life cycle; the host acquires the infection either by ingesting free-living larvae or percutaneously. Earthworms can act as paratenic hosts.

Nematodes aggregate in nodules in the tissues of the inected host, mature, mate, and produce eggs that are passed from the host in urine. Eggs hatch in soil and water. They may be cosumed by earthworms which are ingested by the pigs, or ingested directly from contaminated water. Larvae may also penetrate throgh the skin.. Ingested larvae penetrate into the host blood stream and then to infection sites: kidneys, ureters, amd even liver where they aggregate in nodules and continue development to adults.

   

For Ecophysiological Parameters for this species, click

If species level data are not available, click for genus level parameters


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Damage:

Swine stephanurosis caused by S. dentatus is responsible for economic losses in tropical and subtropical countries in traditional pig production systems (Islam et al., 2015) and also occurs at a high prevalence in wild populations (Sato et al., 2008; Cleveland et al., 2017; Moratal et al., 2018).

Migrating larvae affect mainly the hepatic parenchyma, while adults establish in the urinary system. Loss of apetite, damage to tissues dur to migration, fibrosis and abscess formation (Olsen, 1977; Wang, 2003; Islam et al., 2015).

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Management:

Diagnosis through detection of nematode eggs in urine samples.

Ivermectin anthelmintic treatment of infected pigs.

Reduce infection and transmission by restricting access of pigs to potentially contaminated areas of soil and water.


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References:

Cleveland, C.A., DeNicola, A., Dubey, J.P., Hill, D.E., Berghaus, R.D., Yobsley, M.J. 2017. Survey for selected pathogens in wild pigs (Sus scrofa) from Guam, Marianna Islands, USA. Vet. Microbiol.205:22-25.

Daubney, R.  1923. The kidney worm of swine: a short redescription of Stephanusrus dentatus Diesing 1839, J Comp. Path and Therap. 36-37: 97-103

Deng, Y-P., Zhang, X-L., Li, L-Y., Yang, T., Liu, G-H., Fu, Y-T. 2021. Characterization of the complete mitochondrial genome of the swine kidney worm Stephanurus dentatus (Nematoda: Syngamidae) and phylogenetic implications. Vet. Parasitol. 295 (2021) 109474

Islam, A., Anisuzzaman, Roy, J.R., Yasin, M.G., Labony, S.S., Hossain, M.M., Alim, M.A., 2015. Swine kidney worm in Bangladesh: an abattoir survey. Eurasian J. Vet. Sci. 31: 222-226

Moratal, S., Ruiz de Ybanez,  R., Barroso, P., Granados, J.E., Hofle,  U., Martinez, Carrasco, C., Acevedo, P., Vicente, J., 2018. High prevalence and intensity of Stephanurus dentatus in a population of wild boar (Sus scrofa) in south western Spain. Vet. J. 240:47-49

.Sato, H., Suzuki, K., Yokoyama, M., 2008. Visceral helminths of wild boars (Sus scrofa leucomystax) in Japan, with special reference to a new species of the genus Morgascaridia Inglis, 1958 (Nematoda: Schneidernematidae). J. Helminthol. 82: 159-168.

Verrill, A.E. 1870. Description of Sclerostoma pinguicola. A new species of entozoa from the hog. Amer J Sci and Arts: 223-224

Wang, M., 2003. Veterinary Parasitology, 3rd edition. Chinese Agricultural Press, Beijing, pp. 1-490. in Chinese

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