Molecular confirmation of an abortigenic strain of equine herpesvirus 1 (subtype 1) in a pregnant mare study.

This research study explores the impact of a strain of equine herpesvirus 1 (subtype 1) on four pregnant mares, with results indicating that infections could lead to a variety of outcomes including abortion, birth of sick foals, and birth of healthy foals.

Research Objective and Methodology

• The aim of the study was to determine the effect of equine herpesvirus 1 (EHV-1), subtype 1 on pregnant horses. The virus is known to be abortigenic, meaning it can cause abortion.
• The researchers exposed four pregnant mares to this virus, via both intravenous and intranasal inoculation, during their third trimester of pregnancy.

Results of the Study

• The results varied among the mares: one horse had a miscarriage 15 days after being infected, another gave birth to a sick and weak foal at full term, while the remaining two gave birth to healthy foals at full term.
• Various tissues from the aborted fetus, as well as the thymus of the sick foal, were analyzed by the researchers. They found the EHV-1, subtype 1 virus in these tissues, confirming that the virus was indeed present and active in the infected horses.

Significance of DNA Analysis

• Further to this, DNA restriction endonuclease patterns were studied. These are specific DNA sequences that can be cut by enzymes, and they offer a way to compare different strands of DNA.
• This analysis confirmed that the strain of the virus found in the aborted tissue and the sick foal was same as the original virus used to infect the mares, providing direct proof that the adverse outcomes were due to the inoculated viruses.

Conclusion

• These findings validate previous understanding of equine herpesvirus 1 as a potential cause of abortion or illness in foals. This provides valuable information for future preventative measures or potential treatments.