1. trematodes
  2. characteristics of trematodes
    • generally hermaphroditic
    • complex life cycles
    • all require changes in the intermediate host with some intermediates capable of asexual reproduction
    • flat land can contribute to trematode problem
  3. are trematodes blood suckers?
  4. trematode life cycle
    • egg
    • egg hatch to Miracidium with cilia and swims
    • Miracidium penetrates body of snail
    • in the snail Miracidium morphs to Sporocyst
    • sporocyst (asexually) divides into 10 Rediae
    • 10 Rediae (asexually) divide into 100 Cercariae
    • Cercariae leave the snail, swim to grass where they are consumed by ruminant
    • metamorphoses occurs and they are capable of sexual reproduction

    if weather is in-climate, Cercariae become Metacercariae remaining valiable until warm weather
  5. infective stage
  6. flukes of ruminants
    • Fascioliasis gigantica- giant liver fluke
    • Fascioliasis magna- large liver fluke
    • Fascioliasis hepatica- common liver fluke
    • Dicrocoeliasis lanceatum-lesser liver fluke
  7. the common liver fluke, Fasciola hepatica, lives in the
    bile ducts
  8. etiology of Black's Disease
    • toxin produced by Clostridium novyi
    • (moves from dormant state to vegetative state to produce toxin that kills)

    as flukes migrate through out liver parenchyma, they disturb and activate dormant spores which will activate to vegetative form releasing toxin that will kill in a matter of hrs/days
  9. dog flukes
    • Paragonimus kellicotti
    • Nanophytes salmincola
  10. dog lung fluke
    Paragonimus kellicotti
  11. intermediate host of dog fluke, Paragonimus kellicoti
  12. etiology of Salmon Poisoning
    toxin from Neorickettsia helminthoeca, which is a rickettsial organism carried by the fluke Nanophyetus salmincola

    dog eats salmon=eating Nanophyetus salmincola that carries Neorickettsia helminthoeca causing enteritis in dog
  13. commonly name is the salmon poisoning fluke
    Nanophyetus salmincola
  14. most common fluke
    Alaria canis

  15. cat fluke
    Platynosomum concinnum (formerly called Amphimerus felineus)

    • inhabits bile ducts
    • cats infected following ingestion of lizards or amphibians containing larvae
  16. best times to deworm food producers
    • Easter
    • 4th of July
    • Thanksgiving
  17. National Beef Quality Audit
    • identified liver flukes to be one of the top 10 quality issues facing beef industry
    • identified in 26 states
    • can effect bull fertility
  18. effects of liver flukes on cattle
    reduced pregnancy rates, weaning weights, rate of gain, and bull fertility
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