Student Case Presentation
Evaluation of the causes of pregnancy wastage in bovine cases submitted to the Iowa State University Veterinary Diagnostic Laboratory over a five-year period (2018-2023).
| Date/Time: |
9/12/2024 08
|
| Presenter: |
Chelsea Harris |
| Veterinary School: |
IA |
Abstract:
Economic losses due to pregnancy wastage represents a significant cost for US beef and dairy herds. Diagnosing the cause of bovine abortion can be problematic due to the lack of a reproductive history and or usable diagnostic samples. The purpose of this report was to identify the most common causes of abortion in cases submitted to Iowa State University VDL and to identify specific tissues required for the identification of infectious agents. Over a five-year period (January 2018 – May 2023), there have been 721 bovine reproductive failure cases submitted to Iowa State University VDL including beef and dairy cattle breeds. 673 cases were analyzed for etiological agents, tests and methods, and tissues yielding infectious agents pertaining to their respective diagnosis. Overall, abortions caused by infectious etiologies made up over 40% of all the cases submitted with 60% of these cases being identified with a specific pathogen. The most common infectious causes were Salmonella spp (10.9%) and Listeria monocytogenes (9.5%). Salmonella was identified by bacterial culture of the placenta and stomach contents. L. monocytogenes frequently yielded a positive result via bacterial culture on the fetal stomach contents, liver, lung, and placenta. 398 cases were considered non-infectious, equating to about 60% of the total cases submitted. The most common non-infective causes of abortions were fetal stress (2.3%), trace mineral deficiencies (1.5%), and congenital anomalies (1%). Out of all of the cases submitted, over 64% were classified as idiopathic, primarily due to poor case description and inadequate sampling. Identification of viral agents (IBR and BVD) were limited in this study, constituting only 2.5% of the overall cases. VDL surveys such as this are useful in understanding the most common causes of reproductive failure in cattle.
