Abstract:
Equid herpesvirus type 1 is primarily a respiratory tract virus associated with poor athletic
performance that can also cause late gestation abortion, neonatal foal death and
encephalomyelopathy. Horizontal transmission is well described, whereas evidence of vertical
transmission of equid herpesvirus type 1 associated with the birth of a healthy foal has not
been demonstrated. This study sampled a population of Thoroughbred mares (n = 71), and
their healthy neonatal foals and foetal membranes, to test for the presence of both equid
herpesvirus types 1 and 4 using a quantitative polymerase chain reaction assay. Foetal
membrane swabs and tissue samples were taken immediately post-partum, and venous blood
samples and nasal swabs were obtained from both mare and foal 8 h after birth. Neither equid
herpesvirus type 1 nor equid herpesvirus type 4 nucleic acid was detected in any sample, and
it was concluded that there was no active shedding of equid herpesvirus types 1 and 4 at the
time of sampling. Consequently, no evidence of vertical transmission of these viruses could be
found on this stud farm during the sampling period.
