On January 6, 2020, the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) was notified of two cases of equine abortion in Simcoe County. Both cases were confirmed to be caused by equine herpesvirus type 1 (EHV-1). Both mares aborted during their 10th month of pregnancy, and both mares arrived from an out-of-province location in December.
A third mare was exposed to the infected mares, but she has remained unaffected.
The farm manager kept the new mares separate from the resident mares and in a small group. This type of management procedure reduced the risk of spreading the virus to the entire herd. Working with the facility’s veterinarian, the farm manager isolated the affected mares and has voluntarily placed the premises under quarantine to reduce the risk of viral spread.