Canis ISSN: 2398-2942

Taenia pisiformis

Contributor(s): Stephen Barr

Introduction

Classification

Taxonomy

  • Class: Cestoda.
  • Family: Taeniidae.

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Clinical Effects

Epidemiology

Habitat

  • Adult tapeworm in small intestine of rural and urban dogs that hunt and in other Canidae.
  • Segments and eggs in the environment.
  • Metacestode (cysticercus) on the liver and in the peritoneal cavity of rabbits and hares.

Lifecycle

  • See lifecycle diagram Lifecycle Taenia pisiformis - diagram :
    • Adult tapeworm.
    • Gravid proglottid.
    • Egg.
    • Metacestode (cysticercus).
    • Rabbit/hare intermediate host.

Transmission

Transmission to rabbit/hare
  • Segments migrate out of anus and fall to the ground.
  • Segments passed in feces migrate out onto grass or soil.
  • As segments migrate they leave a trail of thousands of eggs in a gelatinous film over the surface of grass, etc.
  • Eggs left by segments on feces can be eaten by flies and deposited over pasture.
  • Eggs eaten with herbage by rabbits or hares.
Transmission to dog
  • Metacestode (cysticercus) in abdomen of lagomorph eaten by hunting dog or dogs fed rabbit offal.

Pathological effects

  • Very little protective immunity develops in the dog population.
  • Protection (mainly antibody-mediated) can be induced by prior infection in rabbits.

In dog

  • The presence of 1 or many tapeworms usually has little effect on the health of a well-fed dog, burdens are usually only 1-10 tapeworms.
  • Irritation of a segment spontaneously migrating from the anus can cause 'scooting'.
  • Very large numbers of worms in young, poorly nourished dogs could reduce growth rates Tapeworm in a dogs intestine.
  • Very rarely, obstruction of the intestine from many hundreds of worms can occur.

In rabbit, hare

  • Migrating cysts in rabbits' livers induce hemorrhage and inflammation followed by fibrosis. The white migratory tracts result in condemnation of livers in rabbits produced for human consumption.

Control

Control via animal

  • Anthelmintic treatment of dog.
  • Dogs that are free to hunt can be treated regularly, ie every 1-2 months.
  • Uncooked rabbit offal should not be fed to dogs.

Control via chemotherapies

Either Praziquantel Praziquantel.
Or Nitroscanate Nitroscanate.
Or Fenbendazole Fenbendazole.
Or Mebendazole Mebendazole.
Or Dichlorophen Dichlorophen.

Diagnosis

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Further Reading

Publications

Refereed papers

  • Recent references from VetMed Resource and PubMed.
  • Edwards G T & Herbert I V (1980) Some quantitative characters used in the identification of Taenia hydatigena, Taenia ovis, Taenia pisiformis and Taenia multiceps adult worms, and Taenia multiceps metacestodesJournal of Helminthology 55, 1-7 (Speciation).

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