Difference between revisions of "Neospora"

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**In cattle, vertical transmission occurs
 
**In cattle, vertical transmission occurs
 
***Post-natal infection occurs but is less common
 
***Post-natal infection occurs but is less common
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*''Neospora caninum'' in [[Parasitic Myositis#Protozoa|myositis]]
 
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'''Pathogenesis'''
 
'''Pathogenesis'''
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<big>
 
<big>
 
'''[[Neosporosis - Dog|Dog Neosporosis]]
 
'''[[Neosporosis - Dog|Dog Neosporosis]]
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'''[[Neosporosis - Cattle|Cattle Neosporosis]]
 
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'''[[Neosporosis - Horse|Horse Neosporosis]]
 
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</big>
 
  
  
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*''N. caninum''
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*Cattle
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**Necrotising inflammation of muscles
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**Commonest cause of infectious abortion in dairy cattle
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**Myositis more severe than in toxoplasmosis
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**Congenitally infected calves can have encephalomyelitis and paresis
 +
**Abortion usually occurs between 5-7 months of gestation but can occur as early as 3 months
 +
**No other clinical signs in the cow
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**Repeat abortions possible in same cow (persistently infected)
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'''Prevention and Control'''
 +
*Do not allow dogs access to calving cows, placental membranes and aborted or dead calves
  
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''N. caninum'' - A disease of cattle with late abortion of mummified or autolysed foetus. May also get foetal malformation, e.g. arthrogryposis.
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*Do not allow dogs to defecate in cattle feeding areas
  
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==Test yourself with the Tissue Cyst Forming Coccidian Flashcards==
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*Identify and cull seropositive cattle, or do not breed from them or their progeny
  
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[[Tissue_Cyst_Forming_Coccidian_Flashcards|Tissue Cyst Forming Coccidian Flashcards]]
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*Select seronegative cattle for breeding
  
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[[Category:Tissue Cyst Forming Coccidia]]
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*Vaccinate
 +
**Only in the USA
 +
**Neoguard or Intervet
 +
**Killed protozoal vaccine for healthy, pregnant cows
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**Dosed in first 3 weeks of pregnancy and then every 3-4 weeks during gestation
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**Revaccination with 2 doses during each subsequent pregnancy[[Category:Tissue Cyst Foming Coccidia]]
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*Horses
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**Myeloencephalitis
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**Transplacental infection occurs
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**Disease only diagnosed in USA
  
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[[Category:To_Do_-_Parasites]]
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*''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]]

Revision as of 22:44, 9 April 2010

  • 2 main species
    • Neospora caninum in the dog
    • Neospora hughesi in the horse
  • Sporulated oocysts measuring just 10μm
  • Oocyst contains 2 sporocysts with 4 sporozoites
  • Route of transmission not fully understood
  • Often misdiagnosed as Toxoplasma gondii
    • Sarcocystis cysts have thicker walls
  • Infection diagnosed by IFAT, ELISA or PCR
    • Identification of lesions and organisms in tissue using immunohistochemical staining
    • Eliminate other causes of abortion first

Life cycle

  • Life cycle similar to Toxoplasma gondii
  • Limited range of warm-blooded intermediate hosts
    • Asexual reproduction occurs in intermediate host forming tissue cysts
  • Host range of sexual stage is unknown for N.caninum
    • Intermediate host for N.hughesi is the horse, but the definitive host is unknown
  • Final host
    • Dogs pass oocysts
    • Role not fully understood in pathogenesis
    • 5 day prepatent period
    • Other wild canids may also act as final definitive hosts
  • Intermediate host
    • Mostly cattle
    • Natural infection has been documented in other herbivores
  • Transmission
    • Transplacental infection occurs in all intermediate hosts and in the canine final host
      • Transplacental transmission can occur in successive pregnancies
    • In cattle, vertical transmission occurs
      • Post-natal infection occurs but is less common

Pathogenesis Dog Neosporosis


  • Cattle
    • Commonest cause of infectious abortion in dairy cattle
    • Congenitally infected calves can have encephalomyelitis and paresis
    • Abortion usually occurs between 5-7 months of gestation but can occur as early as 3 months
    • No other clinical signs in the cow
    • Repeat abortions possible in same cow (persistently infected)

Prevention and Control

  • Do not allow dogs access to calving cows, placental membranes and aborted or dead calves
  • Do not allow dogs to defecate in cattle feeding areas
  • Identify and cull seropositive cattle, or do not breed from them or their progeny
  • Select seronegative cattle for breeding
  • Vaccinate
    • Only in the USA
    • Neoguard or Intervet
    • Killed protozoal vaccine for healthy, pregnant cows
    • Dosed in first 3 weeks of pregnancy and then every 3-4 weeks during gestation
    • Revaccination with 2 doses during each subsequent pregnancy
  • Horses
    • Myeloencephalitis
    • Transplacental infection occurs
    • Disease only diagnosed in USA
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