Lecture 44 - Flukes Flashcards
describe the 2 origins of trematodes
sexual reproduction = adult worms in definitive host
asexual reproduction = larval worms in snail host
what is the morphology of trematodes
- general flatworm characteristics
- suckers and/or holdfast organs
- incomplete gut
- reproductive organs
T/F: trematodes always have a snail intermediate host
TRUE
describe the nematode life cycle
- snail intermediate host
- encysts in host/vegetation
- ingestion to definitive host
T/F: geography plays an important role in fluke diagnostics
TRUE
what are life cycle highlights of paragonimus kellicotti
- aquatic
- DH = dogs, cats
- 1H = river snails
- 2H = crayfish
what are the 3 liver flukes pertinent to our studies
- fasciola hepatica
- fascioloides magna
- dicrocoelium dendriticum
what are the lifestyle highlights of F. hepatica
- aquatic
- DH = cattle, sheep, goats, camelids
- 1H = pond snails
- 2H = semi-aquatic vegetation
describe the causes of acute and chronic disease of F. hepatica
acute = juvenile flukes migrate through liver parenchyma
chronic = adult worms in bile ducts
how do cattle and small ruminants differ in their chronic disease presentation of F. hepatica
cattle are subclinical presentations whereas small ruminants have clinical signs (rough hair coat, unthriftiness, anemia, bottle jaw, etc.)
what are the production consequences of F. hepatica in cattle and small ruminants
cattle = economic loss (liver condemnation; poor doers)
small ruminants = sudden death or poor doers
how is F. hepatica diagnosed
- fecal sedimentation
- ELISA
- elevated GGT (liver enzyme)
- necropsy findings (liver hemorrhage or bile duct stenosis)
clorsulon kills ___ and albendazole kills ___
adults & migrating juveniles; adults
what are fasciola-associated diseases
- Infectious necrotic hepatitis (C. novyi)
- Bacillary hemoglobinuria (C. hemolyticum)
what are the life cycle highlights of F. magna
- aquatic
- DH = deer/elk
- 1H = pond snails
- 2H = semi-aquatic vegetation
what are dead-end hosts for F. magna, and why
sheep/goats/camelids = death
cattle = walled off in fibrotic cysts
what is the pathology of F. magna in cervids, small ruminants, and cattle
cervids = liver cavitations, subclincal unless heavy infection
small ruminants = severe liver damage, hemorrhage, inflammation, etc.
cattle = subclinical, minor damage
how is F. magna diagnosed
- fecal sedimentation
- necropsy
- dewormer
what is the pathology of D. dendriticum
- non-pathogenic in young animals
- bile duct hyperplasia
- hepatic cirrhosis
- chronic wasting disease
- decreased productivity in old animals
what is a unique intermediate host of D. dendriticum
ants
what is the unique morphology of blood flukes
- dioecious elongate flukes
- female resides in gynecophoric canal of male
what are the life cycle highlights of H. americana
- aquatic
- DH = dogs and raccoons (mesenteric v.)
- 1H = snails
T/F: there are no secondary intermediate hosts for H. americana
TRUE
T/F: ova develop and hatch immeadiately when passed
FALSE - hatch in water
what is the pathology caused by H. americana ova
- infarctions/ischemia of intestinal mucosa
- intestinal dysfunction
- granulomatous rxn in liver and other organs
- inflammation and fibrosis around eggs
how is H. americana diagnosed
- clinical signs = lethargy, anorexia, intermittent V+, bloody liquid D+
- fecal saline sedimentation/smear
- miracidal hatching
- laparotomy
- PCR
- hx of access to water habitats
Describe Nanophyetus salmincola
- salmon poisoning fluke
- infects canids, river snails, fish
- hemorrhagic enteritis
Describe Acanthatrium Oregonense
- potomac horse fever fluke
- infects bats, snails, crayfish
- horse is dead-end host
- colitis, D+, fever
