
An unvaccinated 20-year-old mare in the Municipal District of Taber, Alberta, tested positive for equine herpesvirus-1 after experiencing a full-term colt abortion on April 27. The owner has reported additional abortions on the property, and a voluntary quarantine is in effect.
EDCC Health Watch is a marketing program by Equine Network that uses information from the Equine Disease Communication Center (EDCC) to create and share verified equine disease reports. The EDCC is a nonprofit organization supported by industry donations to provide open access to infectious disease information.
EHV 101
Herpesvirus is highly contagious among horses and can lead to various illnesses, including rhinopneumonitis, abortion in broodmares, and EHM.
Fever is often the primary sign of EHV-1 infection in horses. Other common symptoms in young horses include cough, decreased appetite, depression, and nasal discharge. Pregnant mares typically do not show signs of infection before aborting, which usually occurs late in gestation but can happen earlier. Abortions can occur within weeks to months after EHV-1 infection.
Horses with EHM may initially have a fever and respiratory symptoms before developing neurological signs like incoordination, limb weakness or paralysis, urine retention, loss of tail tone, and recumbency.
Herpesvirus spreads easily through close contact with infected horses, contaminated equipment, or items used by people in contact with infected horses. Biosecurity measures such as hygiene and cleaning practices help prevent disease spread.
While EHV-1 vaccines may reduce viral shedding, they do not protect against the neurological form of the disease. Implementing regular biosecurity measures is crucial for minimizing viral spread and preventing disease outbreaks.

