11/24/2025
‼️ Today’s update on the current EHV-1 and EHM outbreak is there are no new positive cases associated with the rodeo event in Waco, TX. However, a positive EHV-1 case in Madison County, OH has been confirmed and is NOT associated with the Waco, TX outbreak. In addition, Northumberland County, PA confirms an EHV-4 positive case that is NOT associated with the Waco, TX outbreak. The horse was at the Keystone Yearling and Breeder's Sale on Nov 7th and 8th in Bloomsburg, PA.
🦠 What is EHV-4?
EHV-4 is a common DNA virus that is one of the most common affecting horses. In general, EHV-4 causes a respiratory disease that is mild; however, it can cause abortion and very rarely can cause EHM.
🦠 What are the clinical signs of EHV-4?
🤒 Fever
🤧 Nasal discharge
😷 Mild cough
💤 Lethargy
🪦 Neonatal death
🐴 Late-term abortion
🧠 Rarely neurologic disease
🦠 How is EHV-4 diagnosed?
EHV-4 is diagnosed through PCR testing by nasal swab, blood or an antibody titer in serum samples collected 2-3 weeks apart.
🦠 What is the treatment for EHV-4?
Supportive care.
🦠 Is a vaccine available?
Yes, vaccinations are important in reducing disease risk and limiting viral spread. Vaccinations are available to help prevent the respiratory and abortive form of EHV-1 and EHV-4. Currently, there is no vaccine available for the prevention of the neurologic form (EHM).
🦠 How is EHV-4 spread?
Similar to EHV-1, EHV-4 is spread through airborne particles from an infected horse, direct nose to nose contact, contaminated equipment, hands, clothing and etc. and shared water sources.
🦠 It is important to note that horses can be unknown carriers of EHV with the presence of no clinical signs yet can spread the disease to other horses.
🦠 The best way to prevent the spread of the disease is by vaccinating and practicing proper biosecurity.
🔗Please follow this link to the Equine Disease Communication Center: https://equinediseasecc.org/news/article/Equine-Herpesvirus-Myeloencephalopathy-(EHM)-Outbreak
📸: Dr. Laura Javsicas with a special patient. ❤️ Sophia Donohue Photography sophiadonohuephotography
