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Updated: Aug 8, 2026

Development and Validation of a Quantitative PCR Method for Equid Herpesvirus-2 Diagnostics in Respiratory Fluids
Published on: March 17, 2016
Serologic evidence of vesivirus-specific antibodies associated with abortion in horses
Andreas Kurth1, Douglas E Skilling, Alvin W Smith
1Department of Biomedical Sciences, College of Veterinary Medicine, Laboratory for Calicivirus Studies, Oregon State University, Corvallis, OR 97331, USA.
Objective:
To test horses for serologic evidence of an association between vesiviral antibodies and abortion.
Sample Population:
Sera from 141 horses.
Procedures:
2 experiments were conducted. Experiment 1 comprised sera obtained in 2001 and 2002 from 3 groups of horses (58 mares from farms with a history of abortion problems, 25 mares between 3 and 13 years of age with unknown reproductive histories that were sold at auction [breeding-age control mares], and 29 mixed-age males and yearling females sold at auction [negative control population]). Experiment 2 comprised sera from 3 groups of pregnant mares (10 pregnant mares fed Eastern tent caterpillars [ETCs], 9 pregnant mares fed ETC frass only, and 10 pregnant control mares). Sera were analyzed for antibodies against vesivirus by use of a validated recombinant vesivirusspecific peptide antigen in an indirect ELISA.
Results:
For experiment 1, 37 of 58 (63.8%) mares from farms with abortion problems were seropositive for vesivirus antibodies, whereas 10 of 25 (40%) breeding-age control mares were seropositive. All 29 mixed-age males and yearling females were seronegative for vesivirus antibodies. For experiment 2, 17 of 29 mares aborted (some from each group). Seropositive status for vesivirus antibodies increased from 47.1% (8/17) to 88.2% (15/17) for the pregnant mares that aborted during the experiment.
Conclusion And Clinical Relevance:
Significant association was detected between seropositive status for vesivirus and abortion in mares; consequently, vesivirus appears to be a pathogenic virus associated with abortion in mares. These data support adding vesivirus antibody testing into diagnostic screening to determine the cause for abortion in mares.

