Bovine chlamydial abortions

Abstract

Chlamydial agents are obligate intracellular pathogens of prokaryotic pature, and they comprise a large group of antigenically related and culturally, morphologically, and tinctorially similar microorganisms. One property characterizing chlamydial strains of several animal species is their ability to establish placental and fetal infection irrespective of the type of placentation. Chlamydial agents were first suspected as a cause of abortions in cattle in Germany in 1956. Since then they were proven, by isolation from fetuses or placentas, as well as through serological evidence, to be a cause of reproductive failure of cattle. Chlamydiae were identified as a cause of bovine abortions in North America, in most countries of western and eastern Europe, in South Africa, and in some Asian countries.

Characteristics of experimentally induced chlamydial abortions will be analyzed in this contribution from clinical and pathogenetic aspects and from etiological, serological, and pathological viewpoints. In the process, the experimentally induced disease will be compared with, and related to, the more complex problem of abortion that confronts the practitioner and the diagnostician.