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, 10:20, 12 May 2010
*Ovine enzootic abortion
*Especially in intensive systems
*Ewe lambs may acquire infection at birth and abort in their first pregnancy
*Pathogenesis:
**Infection via ingestion or inhalation causes a bacteraemia
**Bacteria localise in placenta and cause placentitis, leading to late abortion or premature weak lambs
**Necrosis of cotyledons and oedema of adjacent tissue, as well as dirty pink uterine discharge
**Aborted lambs well preserved
**Large numbers of chlamydiae shed in placenta and uterine discharges; survive in environment for several days
**Abortion rates may reach 30% in susceptible flock
**Ewes infected late in pregnancy may not abort, but may abort during the next pregnancy
**No other clinical signs in aborting ewes
**Fertility not impaired
*Transmission:
**Survival of elementary bodies in faeces and wild birds are a source of infection from one lambing season to the next
**Ewes may be carriers for several years
**Venereal transmission from infected rams
**Some immunity develops after infection, protecting ewes from subsequent disease
*Vaccination:
**Live attenuated vaccines prior to breeding or inactivated vaccines during pregnancy
**Vaccines prevent infection but will not clear infection from persistently-infected animals
**Vaccination of ewe lambs prior to breeding
*Treatment: long-acting oxytetracyclines during an outbreak to protect in-contact pregnant ewes
*Control: isolate aborted ewes; destroy placentas, thorough cleaning
*Also abortion in cattle, goats and pigs
*Serious infection in pregnant women[[Category:Chlamydophila_species]][[Category:Sheep]][[Category:Cattle]][[Category:Goat]][[Category:Pig]][[Category:Zoonoses]]