Which of the following is most likely to be an equine herpesvirus infection?

Which of the following is most likely to be an equine herpesvirus infection?

• A. A severe and highly fatal respiratory disease that affects horses of all ages
• B. A mild respiratory disease that affects young animals that have been in close contact
• C. A rapidly spreading, severe respiratory disease that affects large numbers of young horses
• D. A severe respiratory disease that affects only immunodeficient foals

Answer: (B)

Equine herpesvirus infections most often present as mild upper-respiratory disease in foals and yearlings that are kept together in groups. This pattern is typical of EHV-4, which spreads through nasal secretions and aerosols and usually causes short-lived signs such as a low-grade fever, mild nasal discharge, and coughing in young horses in close contact. While EHV-1 can lead to more severe outcomes like abortion in pregnant mares or neurologic disease, those are not the common presentation described for a simple respiratory illness in young animals. The scenario described—mild respiratory disease in young horses in close contact—best matches an equine herpesvirus infection.

Equine herpesvirus infections most often present as mild upper-respiratory disease in foals and yearlings that are kept together in groups. This pattern is typical of EHV-4, which spreads through nasal secretions and aerosols and usually causes short-lived signs such as a low-grade fever, mild nasal discharge, and coughing in young horses in close contact. While EHV-1 can lead to more severe outcomes like abortion in pregnant mares or neurologic disease, those are not the common presentation described for a simple respiratory illness in young animals. The scenario described—mild respiratory disease in young horses in close contact—best matches an equine herpesvirus infection.