Trematode Parasites of Veterinary Importance

Question 1

general morphology

Answer 1

dorsoventrally flattened
bilaterally symmetrical
Male & female reproductive organs
Lifecycle involves 2 IH
-mostly aquatic
-1st IH always snail
Parasitic in all systems of vertebrae DH

Question 2

flukes have

Answer 2

flat leaf like body with both male and female reproductive systems

Question 3

Paragonimus kellicoti

Answer 3

Lung fluke
DH: dogs, cats, people
acquired by ingestion of uncooked crayfish
Cause of respiratory disease
Dx by fecal

Question 4

Paragonimus kellicoti respiratory disease symtoms

Answer 4

hard time breathing
dyspnea
pneumothorax in extreme cases

Question 5

Zoonotic paragonimiasis

Answer 5

Foodborne infection acquired from ingestion of raw freshwater crustaceans
Adults live& reproduce in lungs, eggs passed in feces & sputum
Disease associated w inflammatory response to excretory/secretory products
Symptoms: chronic cough fever, bronchitis
may resemble pulmonary tuberculosis

Question 6

diagnostic imaging paragonimiasis

Answer 6

increased alveolar opacity on radiograph
Nodules containing parasites
pleural effusion, pneumothorax
Dx: eggs in sputum, fecal

Question 7

heterobilharzia americana

Answer 7

canine blood fluke
associated w raccoons
Paired adult worms live in mesenteric (male & female)
granulomatous transport through GI
eggs passed in feces
1 IH (snail)
infection by skin penetration!!

Question 8

heterobilharzia americana clinical signs

Answer 8

GI signs (vomiting, diarrhea)
polyuria, polydipsia
liver enzymes normal
early dx may improve prognosis

Question 9

nanophyetus salmicola

Answer 9

salmon poisoning fluke
DH: dogs, cats, fish eating mammals
IH: snail, salmonid fish
acquired by ingestion of metacercaria in kidneys, muscles, &fins of raw salmonid
Zoonotic-> mild GI illness, no Rickettsial
causative agent is Rickettsia!! transovarial transmission

Question 10

Salmon posioning

Answer 10

hemorrhagic enteritis
clinically indistinguishable from canine parvovirus!!!!!!
Dx: clinical signs and trematode eggs in fecal

Question 11

platynosomum fastosum

Answer 11

liver poisoning fluke
DH: felines, bile ducts
IH: snail, pill bugs, geckos possible paratenic?
metacercaria ingested when cats eat lizard
-migrate up bile ducts. adult in bile ducts and gallbladder
vomiting, diarrhea, icterus
Dx: clinical signs and trematode eggs in fecal

Question 12

eurytrema procyonis

Answer 12

raccoon pancreatic fluke
DH: felines, red & grey fox, raccoons
IH: snail, arthropod, possible paratenic
metacercaria ingested by DH
adult worms in pancreatic ducts
-weight loss, vomiting, pancreatitis

Question 13

alaria sp

Answer 13

IH: snail (1st), tadpole and snake (2nd)
DH: cat, dog
MESOcercaria stage
-larval stage capable of being passed one IH to other
-lactogenic transmission!!
adult stage w/ low pathogenicity in GI
aberrant migration of mesocercaria w adverse effects
Zoonotic potential

Question 14

fasciola hepatica

Answer 14

liver fluke
DH: cattle, sheep, goats
acquired by ingestion of metacercaria encysted vegetation
cause of liver disease
-anemia, hypoproteinemia, bottle jaw, progressive weakness, loss of condition

Question 15

fasciola hepatica pathology

Answer 15

fibrosis of liver tissue
hypertrophy of bile ducts
livers condemned @ slaughter

Question 16

distribution of fascioliasis based on

Answer 16

presence/absence of infected hosts
presence of suitable snail IH
suitable soil that promotes moisture retention (snail habitat)
slope, drainage, water runoff
natural & artificial ponds for watering herd

Question 17

clorsulon

Answer 17

binds serum proteins and ingested by fluke
inhibits enzymes important in glycolytic enzyme process
not able to extract energy from glucose, disruption of cellular energy production

Question 18

fascioloides magna

Answer 18

deer liver fluke
DH: white-tailed deer
lifecycle similar to fasicola
adult worms communicate w bile ducts
Non-patent in cattle, sheep, goats (no adult parasite actively reproducing)
Aberrant migration in other ungulate species
-significant tissue destruction
-liver cirrhosis & condemnation @ slaughter

Question 19

paramphistomum sp

Answer 19

rumen fluke
DH: cattle, sheep, goats
acquired by ingestion og metacercaria encysted on vegetation
adult in stomach, non pathogenic
immature stages in duodenum and ileum pathogenic
-necrosis, hemorrhagic inflammatory disease
-hyproproteinaemia
-diarrhea, dehydration
Dx: clinical signs and eggs on fecal

Question 20

dicrocoelium dendriticum

Answer 20

lancet liver fluke
DH: cattle, sheep, goats, etc and bile ducts
IH: snail, ants
miracida hatch from egg when ingested by snail, asexual replication, emerge in slime ball
-ingested by ant, infect brain, remain attached to vegetation
-ingested by grazing DH
metacercaria invade entire biliary system within hours
adult in bile ducts and liver
low pathogenicity
Dx: clinical signs and trematode eggs on fecal

Question 21

parasite infecting respiratory

Answer 21

paragonimus

Question 22

parasite infecting biliary system

Answer 22

fasciola, fascioloides, platynosum, eurytrema, dicrocoelium

Question 23

parasite infecting GI

Answer 23

paramphistomum, alaria, nanophytes

Question 24

prevent trematodes by

Answer 24

breaking the lifecycle

Question 25

Zoonotic trematodes

Answer 25

paragonimus
nanophytes, no rickettsia in humans!!
alaria