Equine Herpes virus (EHV-1) is the leading cause of infectious abortion in mares. Sources for the EHV-1 viral infection include asymptomatic (not showing sickness) carrier mares, clinically ill mares, mares shedding the virus in urine, and infected aborted placenta or an infected fetus. EHV-1 is highly contagious. Along with strict biosecurity measures for your facility, vaccination of your pregnant mare with appropriate vaccinations at 5, 7, and 9 months gestation will prevent abortion and decrease severity of sickness in newborn foals. Please contact us for more information in protecting your pregnant mare.