An attending veterinarian has reported through the Equine Disease Communication Center that a premises in the Municipality of Wallace-Woodworth, Manitoba, has had two Quarter horse mares euthanized due to severe neurologic signs in November.

The first mare was a 7-year-old Quarter Horse that was euthanized on November 9 less than 24 hours after acute onset of neurologic signs, including inability to rise.

A 13-year-old Quarter Horse mare had onset of clinical signs on November 10 that included ataxia an inability to rise. She was euthanized on November 11 and confirmed with herpesvirus on November 14.

The mares were stabled with 38 other horses, and a total of 86 horses of various ages and genders are on the premises. The affected mares were vaccinated for the prevention of EHV-1 abortion approximately one week prior to onset of clinical signs and were approximately five months along in gestation.

As of November 21, no new cases or horses with clinical signs have been reported on the premises. A voluntary quarantine is in place, and to date there is no indication that neurologic herpesvirus has spread from the affected premises.