Parasites in Ruminants Pt 2

ANS 389C

describe the appearance of Dictyocaulus Viviparus

• slender thread-like worms

• white/light grey in color

where are Dictyocaulus Viviparus found?

trachea and bronchi of cattle, buffalo, deer and camels

Dictyocaulus Viviparus is also called…

Bovine Lung Worm

what does Bovine Lung worm cause?

Verminous Pneumonia or Parasitic Bronchitis

what climate do Dictyocaulus Viviparus typically live in?

temperate climates with high rainfall

when are Dictyocaulus Viviparus most clinically significant?

in first year grazing calves

adults have a stronger acquired immunity to Dictyocaulus Viviparus, but they can still be predisposed to what?

decreased weight gain or secondary infecetions

where do Dictyocaulus eggs hatch?

in the bronchi

how do L1 Dictyocaulus enter the GI tract?

they travel up the trachea (from the lungs), and are swallowed to enter the digestive tract

how are L1 Dictyocaulus excreted?

via feces

Dictyocaulus larvae develop into L3 within the feces and climb up the sporangium of ________ ________

Pilobolus fungi

How do Dictyocaulus develop from L3 to L4?

L3 ingested by host and penetrate intestinal mucosa. L3 travel via lymph vessels to lymph nodes where they molt into L4

how do Dictyocaulus develop from L4 to L5?

L4 then travel via blood and lymph vessels to lungs. They then penetrate Alveoli. L5 travel to bronchi where they mature to L5 adults

list the clinical signs of Dictyocaulus Viviparus

• cough

  • mild case - intermittent

  • moderate case - frequent

• labored breathing in severe cases

what do the lungs of a host that’s been infected with Dictyocaulus Viviparus parasites look like?

the surface of infected lungs displays extended emphysematous areas, edema and atelectasis

how are Dictyocaulus Viviparus parasites diagnosed?

• fecal examination

  • Baermann technique

    • detecting larvae in feces

• Eliza testing

• Postmortem exam

  • worms in bronchi and trachea

Fasciola hepatica is also known as…

“Liver Fluke”

where are liver flukes localized?

in the liver Biliary ducts of sheep, cattle, and goats

what is the intermediate host of Fasciola hepatica?

snail

host releases eggs of Fasciola Hepatica when….

they are excreted in feces

upon reaching water, _______ hatches from egg and seeks out snail

Miracidia

what happens once the Miracidium finds a snail (intermediate host)?

Miracidium penetrate snail and develops into Sporocyst

Cercaria erupt from snail and encyst on vegetation as __________

Metacercaria

once ingested, where do Metacercaria hatch?

hatch in intestines

Metacercaria will later leave the intestines after they’ve hatched there. What do they go on to penetrate?

liver (and reside in Biliary Ducts)

how are Fasciola Hepatica diagnosed?

• fecal sediment

• postmortem liver evaluation

• ELISA testing

how are Fasciola Hepatica treated?

• reduce snail exposure in pasture

  • drainage

  • fence off area

  • molluscicide

• anthelmintics

  • albendazole

  • triclabendazole

  • closantel

Moniezia are also known as….

Cestodes

what do Moniezia infect?

the small intestine of sheep, goats, cattle and buffalo

what are Moniezia transmitted by?

mites (specifically Oribatid Mites)

where is infection of Moniezia common in?

lambs, kids and calves during their first year of life

(true/false) Moniezia have little pathogenic significance

true

how is Moniezia diagnosed?

• mature proglottids in feces

• fecal flotation

  • unique shape containing oncosphere

• postmortem exam

what does the Cestoda egg structure consist of?

• oncosphere → a hexacanth (6-hooked) embryo

• embryosphere → a thick, dark, radially striated shell

• shell → delicate membrane; often lost while still in uterus

Moniezia Expansa

triangular shape containing oncosphere

Moniezia Benedini

quandrangular shape containing oncosphere

how are Moniezia treated?

• pasture management

  • alternate pasture for young animals

  • ploughing and reseeding

• anthelmintics

  • albendazole