01/09/2023
Email I got this morning.
Washington County horse tests positive for EHM
A 25-year-old Dutch Warmblood gelding in Washington County was referred to the University of Minnesota on December 28, 2022, due to rear limb weakness, ataxia, and dribbling urine. Samples were submitted for EHV-1 testing, but results were delayed due to the holiday. The horse was euthanized on December 29 due to deterioration in condition. On Janaury 5, 2022, test results came back positive for Equine Herpesvirus Myeloencephalopathy (EHM).
EHM is reportable to the Board because it is highly contagious. The Board collaborated with Minnesota’s equine industry to develop and enforce an official control plan for EHM. In accordance with the EHM Control Plan (https://www.bah.state.mn.us/media/ehm-control-plan.pdf) the Board quarantined 34 horses that were exposed to the EHM-positive horse. All exposed horses are being monitored closely for symptoms consistent with EHV-1 and are having re**al temperatures taken and recorded every 12 hours. Horses displaying clinical signs with temperatures of 102°F or higher are required to be tested for EHV-1. All horses on the premises will remain quarantined until 21 days from when the last elevated temperature was noted, or clinical signs were observed. As of this alert, no additional cases have been identified onsite or associated with the positive horse.
The last case of EHM diagnosed in Minnesota was in March 2022. Multiple cases continue to be identified throughout the United States. The most common way for EHV-1 to spread is by direct horse-to-horse contact. The virus is shed from infected horses via the respiratory tract and is capable of surviving in organic material like manure and feed. Horses may appear healthy yet still spread the virus.
Horse owners are reminded of the importance of adhering to stringent biosecurity practices to prevent the spread of contagious diseases. Diseases like EHM can be carried from one place to another by other horses, people, insects, trailers.