Recently, a horse in Silver Bow County tested positive for equine herpesvirus-1 (EHV-1), with 50 other horses being exposed to the virus. The Montana Department of Livestock is currently investigating this case.
EDCC Health Watch, a program by Equine Network, utilizes information from the Equine Disease Communication Center (EDCC) to provide verified equine disease reports. The EDCC is a nonprofit organization supported by industry donations, offering open access to infectious disease information.
Understanding EHV-1
Equine herpesvirus (EHV) is highly contagious among horses and can lead to various health issues, including respiratory diseases, abortion in broodmares, and Equine Herpesvirus Myeloencephalopathy (EHM).
EHV-1 infection in horses often presents with a fever as the primary symptom, which can go unnoticed. Other signs in young horses may include cough, decreased appetite, depression, and nasal discharge. Pregnant mares may not show signs before experiencing late-term abortions, occurring anywhere from two weeks to several months after infection.
Horses with EHM exhibit fever initially, followed by neurological symptoms like incoordination, weakness or paralysis of limbs, urine retention, loss of tail tone, and recumbency. The virus spreads through close contact with infected horses, contaminated equipment, or contact with individuals who have been in contact with infected horses. Implementing biosecurity measures is crucial for disease prevention.
Vaccines for EHV-1 may reduce viral shedding but do not protect against the neurological form of the disease. Therefore, focusing on routine biosecurity practices is key to minimizing viral spread and preventing outbreaks.

