Introduction
Equine herpesvirus type 3 (EHV-3) belongs to the Order Herpesvirales,
Family Herpesviridae and genus Varicellovirus (Davison,
2010). This virus is the causative agent of the equine coital rash
(ECE), a venereal disease of worldwide distribution which is
characterized by producing lesions in external genitals in foals and
mares (Barrandeguy and Thiry, 2012). The main mechanism of transmission
is the direct contact of genital mucous membranes during intercourse, or
indirectly by fomites (Allen and Umphenour, 2004). Although EHV-3 causes
a localized infection, some authors have speculated that systemic
alterations such as infertility and abortion do occur as well; yet a
systemic pathophysiology is still questionable (Van der Meulen et al.,
2006; Léon et al., 2008; Barrandeguy, 2010).
The impact of the disease is associated with forced and temporary
interruption of mating activities of the affected stallions and mares,
which significantly decreases the number of entries at the end of the
season, provokes a delay in delivery dates and a decrease in pregnancy
rates (Allen and Umphenour, 2004, Barrandeguy and Thiry, 2012). In the
case of infected stallions, a rigid gait, loss of libido and refuse to
mate with mares is common (Barrandeguy and Thiry, 2012; Vissani et al.,
2018). Diagnosis to distinguish between the different types of equine
herpesvirus can be made through PCR (EHV1, EHV2, EHV3, EHV4 and EHV5)
(Wagner et al. 1992; Borchers and Slater, 1993; Kirisawa et al., 1993;
Wang et al., 2007).
Nowadays, the presence of the disease in Latin America has been detected
by molecular tools only in Argentina and Brazil, in clinically healthy
mares and from a foal, respectively (Barrandeguy, 2010). To date in
Chile, the existence of this disease has not been reported (Berrios,
2005). Therefore, the objective of this study was to molecularly
evaluate the presence of this alpha-herpesvirus in equines with the
presence of genital lesions compatible with ECE in this country.