Canis ISSN: 2398-2942

Taenia multiceps

Introduction

Classification

Taxonomy

• Class: Cestoda.
• Family: Taeniidae.
• Genus: Taenia.

Active Forms

Resting Forms

Clinical Effects

Epidemiology

Habitat

• Adult tapeworm in small intestine of rural dogs that are fed sheep heads or scavenge sheep, and in other Canidae.
• Segments and eggs in environment.
• Metacestode (coenurus) in CNS of sheep, goats and occasionally cattle (and man), and in the intramuscular and subcutaneous tissues of goats.

Lifecycle

• See lifecycle diagram  :
  • Adult tapeworm.
  • Gravid proglottid.
  • Egg.
  • Metacestode (cysticercus).

Transmission

Transmission to sheep

• 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 sheep, goats or other animals.

Transmission to dog

• Metacestode (coenurus) in brain (muscles) of sheep  /goat eaten when the dog is scavenging or fed sheep heads.

Pathological effects

• Protective immunity after 2-3 infections in dogs has been described.
• No information is available concerning protective immunity in sheep, but sheep generally become infected in their first year of life.

In dogs

• The presence of tapeworms (1 or many) usually has little effect on the health of a well-fed dog, burdens are usually only 1-13 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 .
• Very rarely, obstruction of the intestine from many hundreds of worms can occur.

In sheep, goats, cattle

• Oncospheres migrating in relatively large numbers in the central nervous system (CNS) of sheep or goats induce inflammation and 'acute' neurological disease 2-3 weeks after infection.
• The majority of cysts grow and cause pressure atrophy in the cerebral hemispheres or elsewhere in the CNS parenchyma; this induces 'chronic' disease of circling, papilledema, blindness, abnormal gait, hyperesthesia, etc.
• In goats, but not sheep, the coenurus can develop, presenting as a mass, in the intramuscular and subcutaneous tissues.

In man

• The coenurus grows primarily in the subarachnoid spaces, cisterns and ventricular spaces, interfering with cerebrospinal fluid pathways.

Control

Control via animal

• Anthelmintic treatment of dog.
• Dogs should be well-fed and prevented from scavenging, and should not be fed raw sheep heads.

Control via chemotherapies

• Anthelmintics have not been approved specifically for efficacy against T. multiceps.
• Drugs with efficacy against Taenia pisiformis should be used.

UK

• Those with efficacy against Taenia hydatigena should be used, ie praziquantel Praziquantel , nitroscanate Nitroscanate , fenbendazole Fenbendazole , mebendazole Mebendazole or dichlorophenamide.

USA

• Drugs to be used include praziquantel Praziquantel , epsiprantel, fenbendazole Fenbendazole.
  Dichlorphenamide is not recommended.

Other countermeasures

Diagnosis