Difference between revisions of "Neospora"

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(Created page with '*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 …')
 
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'''Pathogenesis'''
 
'''Pathogenesis'''
*Dogs
+
<big>
**Occurs mainly in puppies
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'''[[Neosporosis - Dog|Dog Neosporosis]]
**Causes ascending paralysis, especially of hind limbs, with muscle wasting
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**Causes sudden collapse due to myocarditis
 
**More than 1 puppy in a litter may be affected, although this may not occur simultaneously
 
**Successive litters affected
 
  
 
*Cattle
 
*Cattle
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**No other clinical signs in the cow
 
**No other clinical signs in the cow
 
**Repeat abortions possible in same cow (persistently infected)
 
**Repeat abortions possible in same cow (persistently infected)
 
*Horses
 
**Myeloencephalitis
 
**Transplacental infection occurs
 
**Disease only diagnosed in USA
 
 
*''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]]
 
 
 
'''Prevention and Control'''
 
'''Prevention and Control'''
 
*Do not allow dogs access to calving cows, placental membranes and aborted or dead calves
 
*Do not allow dogs access to calving cows, placental membranes and aborted or dead calves
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**Dosed in first 3 weeks of pregnancy and then every 3-4 weeks during gestation
 
**Dosed in first 3 weeks of pregnancy and then every 3-4 weeks during gestation
 
**Revaccination with 2 doses during each subsequent pregnancy[[Category:Tissue Cyst Foming Coccidia]]
 
**Revaccination with 2 doses during each subsequent pregnancy[[Category:Tissue Cyst Foming Coccidia]]
 +
*Horses
 +
**Myeloencephalitis
 +
**Transplacental infection occurs
 +
**Disease only diagnosed in USA
 +
 +
*''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