13. Cattle Helminths 2 Flashcards
What is the lifecycle of dictyocaulus viviparus
PPP is 3-4wks
feces in L1 > L2-L3 (translation period is 5 days in ideal conditions - WET WET WET > ingested and adults complete tracheal migration to lungs > coughed and swallowed to shed
What are the signs of dictyocaulus viviparus How do we control it?
can be subclinical, if clinical, usually calves or previously unexposed cows on wet pasture
coughing (husk), dyspnea, sawhorse stance, bronchopneumonia, morbidity and mortality can be high
Baermans test
control by vx (irradiated L3), given to calves before 1st turnout
anthelmintics: given at midpoint of first grazing season
What major clinical sign does stephanofilaria stilesi cause?
skin lesions like alopecia or scaling
What is the life cycle of stephanofilaria stilesi?
PPP 6-8wks
Microfilariae (L1) in dermis > L1-L3 in hornfly IH > introduced L3 develop to adults in hair follicles
Development in IH: 3wks
How do we dx and tx stephanofilaria stilesi?
present in western cad, dx: microfilaria in skin biopsy
tx: anthelmintic to kill the microfilaria and resolve skin lesions within 2-3wks. adults ressit tx and may survive for years
Where does thysanosoma spp live?
in bile and pancreatic ducts. Has ho rostellum on hooks
does have fringes
What is the life cycle of moniezia spp and thysanosoma spp?
PPP 6 wks
Eggs in feces (immediately infective) > free-living mite intermediate host with cystercercoids (development inmite IH of 1-4mo) > ingested by adults
What is fasciola hepatica?
liver fluke, globally the most important trematode of livestock (but rare to non-existant in west. cad)
grey-brown leaf-shaped fluke primarily in bile ducks
can infect many species - cattle, sheep, goats, deer, horses, pigs, zoonotic’infection occurs only where there is an aquatic snail habitat
What is the lifecycle of fasciola hepatica?
PPP 10-12wks
adults shed eggs in feces > miracidium will penetrate skin of snail > IH: aquatic snail. Asexual repro here and 1000s of cercaria leave > cercariae > metacercaria on vegetation > ingested as adults
Development outside mammalian host is 6wks
What is the pathology of F. hepatica?
adult flukes fed in bile ducts and cause anemia, hypoalbuminaemia, cholantitis
Symptims include progressive loss of condition, emaciation, pale MM, submandibular edema, ascites
Chronic fascioliosis - generally subclinical, reduced growth, fertility probrlms
post-mortem - cholangitis, calcified bile ducts - pipestem liver
How do we dx f. hepatica?
fecal sedimentation - eggs too dense to float, primarily ruminant trematode eggs
What is the fascioloides magna?
giant liver fluide, common in west. cad in cervids like deer, elk and caribou
spill over to domestic livestock
cattle (and moose) are dead end hosts - flukes walled off in liver parenchyma, no eggs shed, no clinical signs, dx at packing plant (no eggs in feces)
sheep also dead end hosts, bur more severe damage to death
control is difficult bc wildlife reservoir
What is the life cycle of fascioloides manga?
adults shed eggs in feces > miracidium > IH snail + sexual repro > cercariae > metacercaria on vegetation > ingested by cattle, sheep, or DH
development outside the host is 6-8wks
What is the dicrocoelium dendriticum?
small fluke that lives in bile ducts
cattle, sheep, deer, rabbits, gophers (people)
worldwide
cypress hills (AB and SK),
crazy ant fluke
What is the life cycle of dicrocoelium dendriticum?
PPP 8wks
adults shed eggs in feces > ingested by snail and miracidium released > slime balls > cercaria > second IH ant w/ metacercaria > development in 2nd IH is about 2 mo
Not an aquatic life cycle
