Related Experiment Video
Updated: Aug 24, 2026
Development and Validation of a Quantitative PCR Method for Equid Herpesvirus-2 Diagnostics in Respiratory Fluids
Published on: March 17, 2016
Detection of EHV-1 and EHV-4 DNA in unweaned Thoroughbred foals from vaccinated mares on a large stud farm
C E Foote1, D N Love, J R Gilkerson
1Department of Biological Sciences, Macquarie University, Sydney 2109, Australia.
Reasons For Performing Study:
A silent cycle of equine herpesvirus 1 infection has been described following epidemiological studies in unvaccinated mares and foals. In 1997, an inactivated whole virus EHV-1 and EHV-4 vaccine was released commercially in Australia and used on many stud farms. However, it was not known what effect vaccination might have on the cycle of infection of EHV-1.
Objective:
To investigate whether EHV-1 and EHV-4 could be detected in young foals from vaccinated mares.
Methods:
Nasal and blood samples were tested by PCR and ELISA after collection from 237 unvaccinated, unweaned foals and vaccinated and nonvaccinated mares during the breeding season of 2000.
Results:
EHV-1 and EHV-4 DNA was detected in nasal swab samples from foals as young as age 11 days.
Conclusions:
These results confirm that EHV-1 and EHV-4 circulate in vaccinated populations of mares and their unweaned, unvaccinated foals.
Potential Relevance:
The evidence that the cycle of EHV-1 and EHV-4 infection is continuing and that very young foals are becoming infected should assist stud farms in their management of the threat posed by these viruses.
