Cestodes Small Animal Flashcards
What is a cestode?
Tapeworm
What is cestode general morphology?
Segmented with proglottids. Mature front to back. Dorsoventrally flattened with no GI structure. Each proglottid can be immature, mature, or gravid
What does “gravid” mean
Produces eggs
What are the two types of cestodes
Cotyloda (pseudotapeworm)
Eucestoda (true tapeworm)
What are the true tape worms
Taenia spp
Dipylidium caninum
Echinococcus spp
Which species is a cotyloda
Spirometra spp
What are the hosts for Dipylidium caninum
Definitive: dogs and cats
Intermediate: fleas, louse
How do you diagnose Dipylidium caninum
Fecal float. Segment squash
What is the lifecycle of Dipylidium caninum
Gravid proglottids are passed intact in the feces. Proglottids disintegrate and release egg packets that are ingested by fleas. Definitive host is infected by ingesting fleas
What are the different species in Taenia spp?
Taenia pisiformis
Taenia hydatigena
Taenia ovis
What are the hosts for Taenia pisiformis?
Definitive host: dog
Intermediate host: rabbit
What is the diagnosis for Taenia spp?
Fecal float or segment squash
What is the lifecycle for Taenia caninum?
Passed proglottid disintegrates and releases eggs that are ingested by the intermediate host. Definitive host eats intermediate, and eggs mature and attach to small intestine
What are the hosts for Taenia hydatigena?
Definitive: canine
Intermediate: ruminant
What is the lifecycle for Taenia hydatigena?
Passed proglottid disintegrates and releases eggs. Intermediate host ingests eggs and they begin to mature. Definitive host eats intermediate host and they mature and attach in small intestine
What is the difference between Taenia hydatigena and Taenia ovis?
Taenia ovus eggs that are ingested by the intermediate host hatch and migrate to muscle.
Which species is a hyatid tapeworm?
Echinococcus spp
How do you diagnose Echinococcus spp?
Adult identification from GI tract. Eggs on fecal float not always definitive. ELISA
What is the main prevention against Echinococcus spp?
Vaccinating sheep & treating at risk dogs for infection. Dogs cannot eat organs of sheep or rodents
What are the hosts of Echinococcus granulosa
Definitive: canine
Intermediate: herbivores (primarily sheep). humans
What is the lifecycle or Echinococcus granulosus
Proglottid is passed and ingested by intermediate host. Egg hatches and larva forms hyatid cysts in organs. Definitive host eats hyatid cysts and matures to adult that attaches in small intestine
What are the different species of Echinococcus spp?
Echinococcus granulosus
Echinococcus multilocularis
What are the hosts for Echinococcus multilocularis?
Definitive: cat & fox
Intermediate: small rodents & humans
What is the Echinococcus multilocularis life cycle?
Proglottid is passed and ingested by intermediate host. Eggs hatch and hyatid cysts become very invasive and form in organs. Definitive host eats hyatid cyst
Which species are reportable?
Echinococcus spp
What are the hosts for Spirometra spp?
Definitive: cat & dog
Intermediate: aquatic crustaceans, fish, reptiles, frogs
What is the lifecycle of Spirometra spp?
Unembryonated eggs are passed and embryonate in the environment. They hatch in water and are ingested by a copepod where they further develop. The copepod is ingested by intermediate host (fish, reptile, amphibian) and develops further. Intermediate host is ingested by definitive
What is the diagnosis for Spirometra spp?
Fecal float
What is the zoonotic danger of Spirometra spp?
Ingesting crustaceans
What does the larval stage of cestodes look like?
Hexacanths. 6 hooks
When is the infective stage of Spirometra spp?
2nd intermediate host (fish, frog, amphibian)
What is the general eucestode lifecycle?
Proglottid is passed and thousands of eggs are released.
When ingested by intermediate host develops into metacestode
When ingested by definitive host, tapeworm emerges and attaches to intestines
What is the general cotyloda lifecycle?
Eggs are passed individually and contact with water makes eggs hatch. Have 2 intermediate hosts (copepod & fish)
