Cestodes of Dogs & Cats

What is the “holdfast” organ in true tapeworms?

Scolex

What is the “hold fast” organ in false tapeworms?

Bothria

Strobila

Chain of individual proglottids

What is the difference in genital pores for false and true tapeworms?

True: located on the sides

False: Located centrally

Cyclophyllideans

True tapeworms

Hexacanth Embryo

Immature tapeworm held in the mature cyclophllidea eggs

Where do cestodes live?

Small Intestine

True or False: Cestodes are hermaphrodites.

TRUE

Common Name: Dipylidium caninum

Flea Tapeworm, Cucumber seed Tapeworm, double-pored tapeworm

Definitive Host: Dipylidium Caninum

Dog, Cat, Humans

Intermediate Host: Dipylidium Caninum

Ctenocephalides felis (Cat Flea)

What is the most common tapeworm in dogs and cats in NA?

Dipylidium Caninum

Route of Infection: Dipylidium Caninum

Ingestion of fleas with metacestode (cysticercoid)

PPP of Dipylidium Caninum

2-3 weeks

Treatment of Cestodes

Praziquantel

How do you treat fleas on the patient?

Isoxazoline drug class

Definitive Host: Taenia Pisiformis

Dog

Intermediate Host: Taenia Pisiformis

Rabbit

Definitive Host: Taenia Taeniformis 

Cat

Intermediate Host: Taenia Taeniformis

Rodents

Morphology of Taenia spp.

• Rectangular proglottids

• Unilateral genital pore that randomly alternates

• Striated shell with hexacanth embryo

PPP of Taenia spp.

1-3 months

Definitive Host: Echinococcus granulosus

Dogs & Wild CanidsI

Intermediate Host: Echinococcus Granulosus

Sheep, Cervids, Humans

Definitive Host: Echinococcus Multilocularis

Foxes, Coyotes, Dogs

Intermediate Host: Echinococcus multilocularis

Rodents & Humans

True or False: Echinococcus and Taenia are hard to differentiate.

TRUE

PPP of Echinococcus spp.

1-2 months

True or False: Dogs are an accidental Intermediate host for E. Multilocularis

TRUE

Best Diagnostic for Echinococcus spp.

Fecal PCR

Definitive Host: Mesocestoides spp.

Dogs, Cats, Mammals

Intermediate Hosts: Mesocestoides spp.

1st: Arthropod

2nd: Reptiles, Amphibians, Mammals, Birds

Which tapeworm has a distinct parauterine organ?

Mesocestoides spp.

PPP of Mesocestoides

2-3 weeks

Peritoneal Larval Cestodiasis

Peritoneal infection with tetrathyridia of Mesocestoides spp. with guarded prognosis

Common Name: Spirometra spp.

Zipper Tapeworm

Common Name: Dibothricephalus spp.

Broad Fish Tapeworm

Definitive Host of Spirometra spp and Dibothriocephalus spp.

Dogs, Cats, Carnivores

Intermediate Host of Spirometra spp.

1st: copepod

2nd: non-fish vertebrae 

Intermediate Host of Dibothriocephalus spp.

1st: Copepod

2nd: Fish

Which parasite can cause a Vitamin B12 deficiency in humans?

Dibothriocephalus

Sparganosis

Plerocercoids of Spirometra proliferate in tissues and result in a poor prognosis

Diagnosis of False tapeworms

Sedimentation

Tetrathyrdia

Metacestode of mesocestoides

Unilocular Hydatid Cyst

E. Granulosus

Multilocular/Alveolar Hydatid Cyst

Metacestode of E. Multilocularis (grape-like)

Cysticercus

Metacestode of Taenia Pisiformis

Strobilocercus

Metacestode of taenia Taeniformis