11/20/2025
FYI-
Equine herpesvirus (EHV) is a highly contagious viral disease that affects both horses and mules, causing respiratory illness, abortion in pregnant mares, and potentially fatal neurological damage (Equine Herpesvirus Myeloencephalopathy, or EHM). It spreads through direct or indirect contact with an infected animal's nasal secretions, aborted fetuses, or placental fluids. Symptoms can range from mild fever and nasal discharge to severe neurological signs like incoordination, weakness, and paralysis.
Symptoms
Respiratory: Fever, coughing, and nasal discharge
Neurological (EHM):
Weakness and incoordination, particularly in the hind limbs
Leaning against objects for balance
Inability to urinate or urine dribbling
Recumbency (lying down and unable to rise)
Reproductive: Abortion, most often in late pregnancy
Neonatal: Foals infected in utero may be born with fever, lethargy, weakness, jaundice, or respiratory distress
Transmission
Direct contact: Nose-to-nose contact with an infected animal
Indirect contact: Through contaminated equipment like buckets, blankets, and tack
Aerosol: The virus can travel through the air over short distances
Fetal material: Contact with aborted fetuses or placental fluids
Latent carriers: Horses that recover from EHV can become latent carriers, with the virus reactivating during periods of stress
Management and prevention
Biosecurity: Practice strict biosecurity measures to prevent the spread of the virus.
Quarantine: Isolate any suspect horses immediately and avoid sharing equipment or water sources.
Veterinary care: Contact a veterinarian promptly if you suspect EHV, especially if neurological signs or abortion occurs.
Sanitation: Regularly clean and disinfect facilities, equipment, and tack.
Supportive care: Treatment for EHV often involves supportive care, including intravenous fluids, anti-inflammatory medications to reduce fever, and antibiotics for secondary bacterial infections.
Antivirals: In some cases, antiviral medications may be used, particularly if given early in the infection.
Reportable disease: In some locations, EHV is a reportable disease, meaning your veterinarian is required to notify the USDA.
