Difference between revisions of "Neospora"

From WikiVet English
Jump to navigation Jump to search
(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 …')
(10 intermediate revisions by 2 users not shown)
Line 40: Line 40:
 
**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
 
*''Neospora caninum'' in [[Parasitic Myositis#Protozoa|myositis]]
 
 
  
 
'''Pathogenesis'''
 
'''Pathogenesis'''
 +
*Dogs
 +
**Occurs mainly in puppies
 +
**Causes ascending paralysis, especially of hind limbs, with muscle wasting
 +
**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
  
<big>
+
*Cattle
'''[[Neosporosis - Dog|Dog Neosporosis]]
+
**Commonest cause of infectious abortion in dairy cattle
 
+
**Congenitally infected calves can have encephalomyelitis and paresis
'''[[Neosporosis - Cattle|Cattle Neosporosis]]
+
**Abortion usually occurs between 5-7 months of gestation but can occur as early as 3 months
 
+
**No other clinical signs in the cow
'''[[Neosporosis - Horse|Horse Neosporosis]]
+
**Repeat abortions possible in same cow (persistently infected)
</big>
 
  
 +
*Horses
 +
**Myeloencephalitis
 +
**Transplacental infection occurs
 +
**Disease only diagnosed in USA
  
*''N. caninum''
+
*''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]]
**Necrotising inflammation of muscles
 
**Myositis more severe than in toxoplasmosis
 
  
''N. caninum'' - A disease of cattle with late abortion of mummified or autolysed foetus. May also get foetal malformation, e.g. arthrogryposis.
+
'''Prevention and Control'''
 +
*Do not allow dogs access to calving cows, placental membranes and aborted or dead calves
  
==Test yourself with the Tissue Cyst Forming Coccidian Flashcards==
+
*Do not allow dogs to defecate in cattle feeding areas
  
[[Tissue_Cyst_Forming_Coccidian_Flashcards|Tissue Cyst Forming Coccidian Flashcards]]
+
*Identify and cull seropositive cattle, or do not breed from them or their progeny
  
[[Category:Tissue Cyst Forming Coccidia]]
+
*Select seronegative cattle for breeding
  
[[Category:To_Do_-_Parasites]]
+
*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[[Category:Tissue Cyst Foming Coccidia]]

Revision as of 22:41, 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

  • Dogs
    • Occurs mainly in puppies
    • Causes ascending paralysis, especially of hind limbs, with muscle wasting
    • 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
    • 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)
  • Horses
    • Myeloencephalitis
    • Transplacental infection occurs
    • Disease only diagnosed in USA

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