Cattle & Sheep Non-GI Worms Flashcards
What is the life cycle of Dictyocaulus viviparus?
What is the life cycle of protostrongylids?
What is the life cycle of Stephanofilaria stilesi?
What is the life cycle of Setaria spp.?
What is the life cycle of Moniezia spp & Thysanosoma spp?
More pathogenic in sheep, esp. lambs (D+, weight loss)
What is the life cycle of Taenia ovis (ovine cysticercosis)?
What is the life cycle of Taenia saginata (bovine cysticercosis)?
What is the life cycle of Fasciola hepatica?
What is the life cycle of Fascioloides magna?
What is trematode disease in sheep with Fasciola hepatica?
- normal DH
- acute fasciolosis (migration of juvenile flukes in liver ingested in short time span)
- liver damage & hemorrhage
- sudden death, anemia, hypoalbuminemia, submandibular edema, ascites, dyspnea, abdominal pain occurring 2-6 wks after infection, eggs present
What is trematode disease in sheep with Fascioloides magna?
- aberrant DH
- nonpatent infections
- flukes migrate around the liver & cause significant tissue damage
- aberrant hosts usually die w/in a few months of infection (BEFORE PATENT)
What is the life cycle of Dicrocoelium dendriticum?
Who is this shed stage?
L1 larvae of Dictyocaulus viviparus from FRESH feces
Who is this shed stage?
L1 larvae of Dictyocaulus filaria found in feces (Baermann)
- anterior cone
Who is this shed stage?
Dorsal spined larvae
- Muellerius (sheep & goats)
- Parelaphostrongylus spp. (wild cervids)
Who is this shed stage?
Protostrongylus or spiked tail larvae
- Protostrongylus (bighorn & thinhorn sheep)
- Orthostrongylus (wild cervids)
Who is this shed stage?
Dictyocaulus larvae
- D. viviparous (cattle)
- D. filaria (sheep)
Who is this shed stage?
Moniezia sp. egg shed in feces
Who is this shed stage?
Thysanosoma sp egg packet shed in feces
Who is this shed stage?
Taeniid egg shed in feces
Who is this shed stage?
Taeniid gravid segment shed in feces
Who is this shed stage?
Fasciola hepatica eggs shed in feces
Who is this shed stage?
Dicrocoelium dendriticum eggs shed in feces
Diagnostic test for Dictyocaulus viviparous?
Baermann on FRESH samples
Diagnostic test for Dictyocaulus filaria?
Baermann on FRESH samples
How do we diagnose Stephanofilaria stilesi?
clinical symptoms, microfilaria in skin biopsy
How do we diagnose Taenia ovis?
- no clinical signs associated w/ adult stages in dogs or cysticerci in sheep
- at post-mortem, cysticerci in skeletal muscle & heart lead to carcass condemnation (not a zoonosis)
- increasing cause of concern for sheep producers in western Canada
How do we diagnose Fasciola hepatica?
- fecal sedimentation (eggs too dense to float)
- coproantigen, antibodies in bulk tank milk
- bloodwork: +/- anemia, hypoalbuminemia, eosinophilia, elevated liver enzymes
- liver pathology on post-mortem or meat inspection
Who is this shed stage?
Fasciola Hepatica eggs in fecal sedimentation
What is chronic fasciolosis in Cattle?
- adult flukes in bile ducts
- generally sub-clinical
- reduced growth & fertility, progressive loss of condition
- post-mortem: chronic cholangitis, calcified bile ducts
What condition can migrating flukes trigger in all livestock?
clostridial disease
- flukes activate clostridia spores in the liver (bacillary hemoglobinuria aka redwater disease)
- clostridia is a bact that produces spores which are ingested & live in the rumen & liver of healthy cattle, damage by liver flukes cause these spores to germinate & can produce a toxin that can destroy RBCs
How do we control for Dictyocaulus viviparous?
- vaccine (irradiated L3) used in Europe, given to calves before 1st turnout
- anthelminthics (esp MLs): are given at midpoint of 1st grazing season
How do we treat for Stephanofilaria stilesi?
- ML kill the microfilaria & resolve skin lesions w/in 2-3 wks
- adults resist treatment & survive for years
Who is this? & where are they found?
- no rostellum or hooks
- wider than long
Moniezia spp.
intestines
Who is this? & where are they found?
- no rostellum or hooks
Thysanosoma spp.
intestines, bile & pancreatic ducts
How do we control for Taenia ovis?
- no treatment for sheep
- treat dogs w/ praziquantel AT LEAST 2x per year
- prevent dogs from eating infected sheep carcasses
- prevent dogs (& coyotes) from pooping on sheep feed & pasture
How do we control & treat for Taenia saginatta in definitive hosts?
- treatment of carrier people w/ cestocides
- goal: halt environmental contamination w/ immediately infective eggs
- prevent access to IH (raw or undercooked meat in endemic regions)
- cook meat to the safe internal temperature (160 F / 71 C)
How do we control & treat for Taenia saginatta in intermediate hosts?
Cattle
- no treatment available or suitable
- meat inspection
- prevent livestock access to human feces
CFIA control of Bovine cysticercosis in Canada?
- REPORTABLE DISEASE under Health of Animals Act: meat inspectors, vets, & labs must IMMEDIATELY report EVEN SUSPICION of disease to CFIA DISTRICT VET
CFIA - quarantine premises & source farms
- license remaining animals to slaughter
- make recommendations to halt transmission
- lift quarantine/open feedlot after certain number of the animals are negative
Why is control of Fascioloides magna difficult?
wildlife reservoir (deer, elk, caribou are DH)
How do we control for flukes in cattle & sheep?
- rarely necessary in Western Canada in cattle
- prevention: avoid known contaminated pastures, avoid liquid manure as fertilizer from infected herds near water, prevent livestock access to wetlands & cervid access to pastures
- control in problem herds: treatment of all exposed ruminants on farm, CLOSANTEL (FLUKIVER) OR TRICLABENDAZOLE IN FALL (resistance observed to latter in Europe) to kill juvenile flukes - SHEEP
- albendazole in early winter to kill adult flukes - DAIRY
- vaccination for clostridial diseases (at least every 6 months)
