Chlamydia psittaci: is tonsillar tissue the portal of entry in ovine enzootic abortion?

Ewes at 70 days of gestation were exposed by various routes to a culture of Chlamydia psittaci. Chlamydial infection of fetal tissues, generally accompanied by abortion, was observed only in four of six ewes inoculated via the tonsillar crypts and in five of seven ewes injected subcutaneously; most of these also developed antibodies to C psittaci. Seroconversion after normal lambing was also observed in most ewes inoculated orally or by stomach tube, despite failure to detect chlamydia in them.