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| − | ===''Chlamydophila abortus''=== | + | ===''[[Chlamydophila abortus]]''=== |
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| − | *Ovine enzootic abortion
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| − | *Especially in intensive systems
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| − | *Ewe lambs may acquire infection at birth and abort in their first pregnancy
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| − | *Pathogenesis:
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| − | **Infection via ingestion or inhalation causes a bacteraemia
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| − | **Bacteria localise in placenta and cause placentitis, leading to late abortion or premature weak lambs
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| − | **Necrosis of cotyledons and oedema of adjacent tissue, as well as dirty pink uterine discharge
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| − | **Aborted lambs well preserved
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| − | **Large numbers of chlamydiae shed in placenta and uterine discharges; survive in environment for several days
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| − | **Abortion rates may reach 30% in susceptible flock
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| − | **Ewes infected late in pregnancy may not abort, but may abort during the next pregnancy
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| − | **No other clinical signs in aborting ewes
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| − | **Fertility not impaired
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| − | *Transmission:
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| − | **Survival of elementary bodies in faeces and wild birds are a source of infection from one lambing season to the next
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| − | **Ewes may be carriers for several years
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| − | **Venereal transmission from infected rams
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| − | **Some immunity develops after infection, protecting ewes from subsequent disease
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| − | *Vaccination:
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| − | **Live attenuated vaccines prior to breeding or inactivated vaccines during pregnancy
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| − | **Vaccines prevent infection but will not clear infection from persistently-infected animals
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| − | **Vaccination of ewe lambs prior to breeding
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| − | *Treatment: long-acting oxytetracyclines during an outbreak to protect in-contact pregnant ewes
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| − | *Control: isolate aborted ewes; destroy placentas, thorough cleaning
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| − | *Also abortion in cattle, goats and pigs
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| − | *Serious infection in pregnant women
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