Bedsonia Abortion of Sheep

Autor: D.G. McKercher, Michael J. Studdert
Rok vydání: 1968
Předmět:
Zdroj: Research in Veterinary Science. 9:331-336
ISSN: 0034-5288
DOI: 10.1016/s0034-5288(18)34546-6
Popis: SUMMARY The epizootic bovine abortion (EBA) agent when inoculated subcutaneously, intravenously, orally or intranasally into fully susceptible ewes, i.e. those with no demonstrable complement fixing (CF) antibody to the Bedsonia group antigen, at approximately 6 weeks of gestation caused abortion or premature birth after a minimum incubation period of 56 days. The syndromes observed following experimental inoculation of the EBA and the enzootic abortion of ewes (EAE) agent resembled each other and both resembled the naturally occurring disease EAE. The 50% infective dose of the EBA agent required to cause abortion in fully susceptible ewes is less than 500 chick embryo lethal doses (ELD50). Attempts to demonstrate that perinatal infection of ewe lambs, or infection of non-pregnant ewes, subsequently results in abortion, were unsuccessful. The meaninterval between parenteral inoculation of the EBA or EAE agent and abortion was 73 days, while for ewes receiving the EBA agent orally the interval was 82 days. Evidence is presented that the EBA and EAE agents elaborate a toxin, and an early abortion syndrome believed to be an experimental artefact caused by this toxin is described. The role of toxin in typical Bedsonia abortion was not ascertained, although it is believed to be minor. Abortion was produced in sheep following inoculation of the sheep pneumonia (SP) agent. This abortion differed in several ways from typical EAE.
Databáze: OpenAIRE
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