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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**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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'''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 | ||
| − | + | *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 | ||
| − | *'' | + | *''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]] |
| − | |||
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| − | '' | + | '''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 | |
| − | [[Category: | + | *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
- Transplacental infection occurs in all intermediate hosts and in the canine final host
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
- Neospora caninum in myositis
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