Diagnostic frameworks and abortifacient findings in domestic ruminant abortions: a multicountry European study (2022–2024)

Background Reproductive loss in ruminants, including abortion, premature birth, stillbirth, the birth of weak offspring, and occasionally early embryonic death, can result from numerous causes. Infectious agents may cause abortion “storms” affecting multiple animals within a herd/flock and may pose a significant zoonotic risk. Methods This report aims to provide an overview of the procedures governing diagnostic investigation and reporting of ruminant abortions across six European countries (Belgium, France, Germany, Spain, the Netherlands, and the United Kingdom) and summarise the predominant abortifacient agents identified in ruminant abortion cases through national diagnostic surveillance frameworks between 2022 and 2024. Results Findings underscore notable divergence in approaches to abortion diagnostics, both in laboratory methods and in the scope of surveillance and reporting systems, which range from centralised national frameworks to decentralised regional structures or voluntary schemes. This heterogeneity limited the comparability of data between countries, although the main bacterial, parasitic, and viral abortifacients identified were broadly similar across countries. Conclusions These findings support the need for greater harmonisation, mainly regarding coverage, diagnostic interpretation principles, and centralised consolidated data collection and reporting, in order to improve comparability across countries, particularly given the transboundary and zoonotic potential of abortifacient agents.