Diagnoses in 1,784 ovine abortions and stillbirths

Of 1,799 accessions of ovine abortions and stillbirths by the South Dakota Animal Disease Research and Diagnostic Laboratory during a 10-year period, 1,784 were suitable for examination. Etiologic diagnoses were made in 786 (44%). Infectious agents were found responsible in 702 accessions (39%), and noninfectious causes were involved in 84 (5%). No diagnosis was made in 998 accessions (56%), 61 of which were mummified fetuses. Lesions, most of which indicated the presence of an infectious agent, were found in 274 cases (15%) in which no agent could be identified. Together, Toxoplasma gondii, Campylobacter sp., and Chlamydia psittaci caused approximately 25% of all abortions and stillbirths examined.