On March 27, the Michigan Department of Agriculture and Rural Development confirmed the first case of equine herpesvirus myeloencephalopathy (EHM) for 2018. The first EHM case was in a 5-year-old Standardbred gelding from Washtenaw County.
The horse was immediately quarantined off-site and 16 other horses were quarantined at the facility where the horse had originated. The 16 horses were monitored twice a day for fevers and sign of herpesvirus, starting the day the EHM-positive horse was removed from the premises.
As of April 17, the other 16 horses have had 21 consecutive days without the presence of fevers or clinical signs and have been released from quarantine. The EHM-positive horse is currently recovering and being quarantined at a separate premises, where there are no equine within 30 feet of the property.