Author, Donkey, Bureaucrats, Administrators
53,803
edits
Changes
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 …'
*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
*''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|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[[Category:Tissue Cyst Foming Coccidia]]
**''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
*''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|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[[Category:Tissue Cyst Foming Coccidia]]