Neospora: Difference between revisions

Revision as of 22:46, 9 April 2010

2 main species
- Neospora caninum in the dog
- Neospora hughesi in the horse

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

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

Horses
- Myeloencephalitis
- Transplacental infection occurs
- Disease only diagnosed in USA

@@ Line 42: / Line 42: @@
 '''Pathogenesis'''
 <big>
 '''[[Neosporosis - Dog|Dog Neosporosis]]
+'''[[Neosporosis - Cattle|Cattle 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[[Category:Tissue Cyst Foming Coccidia]]
 *Horses
 **Myeloencephalitis
@@ Line 73: / Line 54: @@
 *''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]]
+[[Category:Tissue Cyst Foming Coccidia]]