Neosporosis in a Dairy Herd

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Neosporosis in a Dairy Herd

• Jenny Cigan and Tyler Schaaf

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Problem

• Herd manager for a 3000 cow dairy herd
• Herd is vaccinated for a variety of different
  diseases and AI is used on all cows
• Seeing an abortion rate of 20 in first lactation
  heifers after 4-6 months of gestation
• Suspect Neosporosis

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Neosporosis

• Caused by very small single celled protozoa
  called Neospora canium
• Causes abortions in mid gestation in cattle,
  sheep, goats, dogs, and horses
• Outbreaks occur in herds that may be stressed
  from other disease or that have never been
  exposed to the parasite before

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Transmission

• Dog is the definitive host- where parasites
  produce infective eggs
• Cow is the intermediate host- ingests the eggs
  and becomes infected

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Two Modes of Transmission

• 1. Ingestion of parasite eggs shed in feces of
  infected canines
• 2. Transmission of the parasite from an affected
  cow to her calf in utero
• Dogs can also be infected by ingesting placentas
  from infected cows, propagating the cycle

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Symptoms

• No clinical signs either before or after abortion
• Diagnosed through microscopic examination of
  placentas or aborted fetuses or through blood
  tests

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Impact on Production

• Loss of 20 of calves from first lactation
  heifers is a huge economic loss
• Infection lowers milk production an average of
  760lbs per lactation
• Mastitis is more prevalent in infected cattle

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Treatment

• No vaccines or treatments for the disease are
  currently available
• Once infected, cattle have the disease for the
  rest of their life

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Control Measures

• Prevent canines from contaminating cattle feed or
  water
• Do not leave placentas or aborted fetuses in the
  pasture for wild dogs to consume
• Test any new animals coming into the herd for
  Neosporosis
• Cull infected animals if feasible

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Job Security?

• Should we be fired?
• No, but action should be taken to insure no more
  infection by canine contamination occurs

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Neosporosis

• Questions?
• Jenny Cigan and Tyler Schaaf