Ruminant Helminths Flashcards
what is the general life cycle of GI strongylida?
direct
what unifies the hot complex?
strongyle-type eggs
what is Haemonchus contortus important in?
small ruminants
what do Haemonchus spp do to get through winter?
arrested larval development
what do Haemonchus spp feed on?
blood
what are the clinical signs of Haemonchus spp?
hyperacute, acute, chronic forms
anemia
edema
melena
death
what GI nematode is of major importance in cattle?
Ostertagia ostertagi
where do the L3 of Haemonchus spp go?
between gastric epithelial cells
where do the L3 of Ostertagia ostertagi go?
in gastric glands of abomasum
what is type I ostertagiosis?
recently ingested L3 develop to adults without arrested larval development
young cattle grazing pasture for first time
what is type II ostertagiosis?
arrested L4 resume development weeks-months after L3 ingested
usually 2-4 years of age
what are the clinical signs of ostertagia and teladorsagia?
diarrhea
weight loss
dehydration
hypoproteinemia
where does Trichostrongylus axei inhabit?
abomasum in ruminants
stomach in horses
where does Trichostrongylus colubriformis inhabit?
small intestine in ruminants
where does Cooperia spp inhabit?
small intestine
cattle, small ruminants
where does Oesophagostomum spp inhabit?
large intestine
not usually primary pathogens
what is the pathophysiology of Oesophagostomum spp?
hemorrhagic or purulent nodules
mucus
leakage of blood and plasma proteins
where does Nematodirus spp inhabit?
small intestine
what is the important species in Nematodirus spp and what does it infect?
N. battus
sheep
what development occurs in the egg of Nematodirus spp?
L1-L3
where do Bunostomum spp inhabit and what do they eat?
small intestine
blood
what life cycle do Bunostomum spp have?
direct
how does Bunostomum spp usually infect the host?
skin penetration
what are the clinical signs of Bunostomum spp?
irritation of skin at entry point
loss of villi, hemorrhagic lesions, diarrhea, emaciation, anemia, hypoproteinemia
death in heavy infections
what life cycle do Strongyloides papillosus have?
free-living alternating with parasitic
when are the peak infections of Strongyloides papillosus in ruminants?
1-3 month old calves
2-6 week old lambs/kids
what are the clinical signs of Strongyloides papillosus?
calves and lambs: cardiac arrest
goats, small ruminants: diarrhea, anorexia, ataxia
what is the direct life cycle infectious stage in Trichuris spp?
L1 in egg
what is the most common cestode of ruminants?
Moniezia
what life cycle do Moniezia spp have?
indirect
what is the life cycle of Fasciola hepatica?
indirect
intermediate host is aquatic snail
is Fasciola hepatica zoonotic?
yes
what does Fasciola hepatica cause?
biliary duct hyperplasia and fibrosis
cholangitis
anemia
what are the clinical signs of Fasciola hepatica?
acute disease: anorexia, anemia, jaundice, ascites, depression, death
subacute disease: decreased weight gain, liver failure, anemia, death
chronic disease: emaciation, anemia, bottle jaw, subtle production losses
what are the hosts of Fascioloides magna?
natural: cervids
aberrant: sheep and goats
dead-end: cattle, pigs, llamas, horses, moose
what are the clinical signs of Fascioloides magna in aberrant and dead-end hosts?
aberrant: uninterrupted migration of larvae through liver: chronic disease, sudden death
dead-end: thick-walled capsules of adult flukes in liver, may not have disease
what does Dictyocaulus viviparus infect?
cattle and cervids
where does Dictyocaulus spp infect?
trachea, bronchi, bronchioles
describe the life cycle of Dictyocaulus viviparus
direct
L3 infective
L1 in feces
L3 ingested to small intestine
to lungs
what are the clinical signs of Dictyocaulus viviparus?
respiratory: chronic bronchitis, tachypnea, crepitation
anorexia
febrile
death
what is the life cycle of Muellerius spp?
indirect
intermediate host: snail
what is the life cycle of Parelaphostrongylus tenuis?
indirect
intermediate host: snail
what does Parelaphostrongylus tenuis do?
brain worm or meningeal worm
what are the clinical signs of Parelaphostrongylus tenuis?
none in natural host
abnormal: encephalitis, neurological signs
what transmits Thelazia and where do they infect?
flies
eyes