12 Trematodes + Acanthocephalans Flashcards
What are the characteristics of trematodes?
-Nonsegmented flat worms
-Ventral and oral suckers
-No body cavity
-Blind ended GI tract
-Often hermaphroditic
Schistomes are _______(hermaphroditic/separate sexes).
Separate sexes
Where in the body do schistosomes live?
Intravascular
What lesions do Fasciola hepatica cause?
Severe periportal fibrosis and cholangiohepatitis
What kind of parasites are in order Digenea?
Flukes/trematodes
Describe the life cycle of a digeneic trematode.
Adult lays egg –> egg hatches to free swimming miracidium –> sporocyst forms in aquatic snail –> asexual repro in the snail to form daughter sporocysts–> motile cercaria leaves snail –> metacercaria encysts on vegetation OR in second intermediate host waiting to be ingested by host
What kinds of animals are affected by digenean trematodes?
Bird and terrestrial vertebrates
Monogenean trematodes affect what kind of animals?
Fish, amphibians, aquatic vertebrates
Fasciola hepatica thrives in _______ (wet/dry) environments.
Wet
What species are affected by Fasciola hepatica, and where do the adult trematodes live in the host?
Ruminants; bile ducts
How is fascioliasis diagnosed?
Fecal sedimentation
What are the clinical signs of fascioliasis?
Weakness, anemia, diarrhea, hypoproteinemia, poor weight gain, poor milk production
What are the definitive and dead end hosts of Fascioloides magna?
Cervids (deer) –> definitive
Ruminants –> dead end
What species and organ do Paramphistomum spp affect?
Rumen fluke of ruminants
T or F: Paramphistomum spp are highly pathogenic and will always cause disease.
F, adults usually don’t cause disease unless there is a heavy burden that causes diarrhea/enteritis
How can fluke infestations be controlled around domestic animals?
Ducks can eat mollusks
Dry the pasture
Molluskicides are quite toxic and may poison vertebrates
What is the causitive agent of salmon poisoning disease in dogs?
Neorickettsia helminthoeca
What is the causitive agent of Potomac horse fever?
Neorickettsia risticii
What is the name of the fluke that carries salmon poisoning disease, and is the fluke pathogenic?
Nanophyteus salmincola; not pathogenic
What are the clinical signs and lesions of salmon poisoning disease?
-Fever 5-7 days after ingestion
-Dehydration, anorexia
-Vomiting, diarrhea
-Hemorrhagic enteritis
-Lymphadenomegaly
What intermediate host(s) do Nanophyteus salmincola use?
1st – snail
2nd – fish
How is salmon poisoning disease treated?
Tetracyclines and supportive care
T or F: If a dog is showing clinical signs of salmon poisoning disease, you should be able to diagnose the fluke via fecal sedimentation prior to treatment.
F; usually symptoms start before the eggs appear in the feces. If you suspect salmon poisoning, treat it even without presence of eggs
What is another name for Potomac horse fever?
Equine monocytic ehrlichiosis
What are the clinical signs of Potomac horse fever?
VARIED
-Diarrhea
-Dehydration
-Colic
-Fever
-Depression
How is Potomac horse fever prevented?
Vaccination
How is Potomac horse fever diagnosed?
PCR or IFA serology assay
What is the definitive host of the parasite that carries Neorickettsia risticii?
Bats
What species and organ do Paragonimus kellicoti affect?
Terrestrial carnivores; lungs
What intermediate host(s) do Paragonimus kellicoti use?
1st – snail
2nd – crayfish
What are the lesions and clinical signs of pulmonary flukes of carnivores?
Multifocal pneumonia, bronchiectasis, intermittent coughing
How do Schistosomes cause disease?
Egg emboli in tissues
Where are adult Heterobilzharia americana found?
Mesenteric or portal veins
What lesions do Heterobilzharia americana cause?
Multifocal fibrosis and portal granulomas
What is the common name for cercarial dermatitis in humans?
Swimmer’s itch
What organism (general type, not scientific name) causes swimmer’s itch?
Schistosomes of bird
What are the characteristic of acanthocephalans?
-Nonsegmented body
-Armed rostellum
-Lack GI tract
-Separate sexes
What intermediate hosts do acanthocephalans use?
Arthropods
What domestic species can acanthocephalans affect, and how frequent are infections?
Dogs, cats, pigs; rare
Where in the body to acanthocephalans live, and how can they cause disease?
Small intestine; can cause peritonitis via gut perforation
