Trematodes Small Animal Flashcards
What is the general morphology of trematodes?
Unsegmented, flattened, vast size variation. Can be leaf shaped or worm like (schistosomes). Hermaphroditic except for schistosomes
What are the two types of schistosomes?
Monogenetic: single host for entire lifecycle
Digenetic: 2-4 obligate host with potential parratenic host
What is the internal anatomy of trematodes?
GI tract with mouth sucker. No body cavity
Where can trematodes infect in the body?
Rumen/reticulum, intestines, liver, bile duct, lungs, blood vessels
Which trematode is known as the “salmon poisoning fluke”?
Nanophyetus salmincola
Which trematode is the smallest fluke?
Nanophyetus salmincola
What are the hosts for Nanophyetus salmincola?
Definitive: canine & other carnivores
1st intermediate: fresh water snail
2nd intermediate: salmon
How do you diagnose Nanophyetus salmincola?
Fecal float
What is the lifecycle for Nanophyetus salmincola?
Adults in the small intestine pass eggs that hatch into miracidium. Miracidium enter into snail and mature into cercaria, then are released into water and penetrate salmon. Mature in salmon to meacercaria, then fish is eaten by definitive host where it matures into an adult
What is the potential zoonosis for Nanophyetus salmincola?
Undercooked fish
Which fluke is known as the “lung fluke”?
Paragonimus kellicotti
What is the definitive host for Paragonimus kellicotti?
Definitive: canine, feline & other carnivores
Intermediate: operculated snail & crayfish
What can Paragonimus kellicotti cause in the body?
Cystic nodules on the lungs
What is the diagnosis for Paragonimus kellicotti?
Fecal float/sedimentation or radiology
What is the lifecycle for Paragonimus kellicotti?
Eggs are coughed up & reswallowed, then passed through feces. Eggs hatch into miracidium that penetrate snail, where they mature to cercaria, exit the snail, and infect crustacean. Encyst in tissues, then crustacean is eaten by definitive host, where it migrates to the lungs
Which fluke is called the “circulatory fluke”?
Schistosomes
What is the host of schistosomes?
Definitive: canines & raccoons
Intermediate: freshwater snail
T/F schistosomes are dioecious?
True
How do you diagnose schistosomes?
Fecal sedimentation in fresh water. ELISA/PCR
What is the zoonotic potential of schistosomes?
Swimmers itch
What is the lifecycle of schistosomes?
Adults copulate in the mesenteric veins, then enter into intestinal wall and other organs. Eggs passed through feces and hatch in the water. Miracidium penetrate the snail and mature to cercaria, then exit and penetrate host skin/mucous membranes. Migrate into lungs & liver and access mesenteric veins
What is the general lifecycle of trematodes?
Eggs are passed. Hatch in water into “miracidium” which are motile. Miracidium penetrates and matures to “cercaria.” Cercariae can penetrate skin, attach to vegetation & encyst, or penetrate second intermediate host where is matures to adult
