Equine herpesvirus type 1 neurological disease and enterocolitis in mature standardbred horses.

The study documents cases of Equine herpesvirus type 1 (EHV-1), which can cause various health problems such as respiratory diseases and neurological problems in horses. The paper makes significant inroads by being the first to report spontaneous enteric (gut-related) complications due to EHV-1 infection in mature horses.

Introduction and Background

• Equine herpesvirus has two antigenically similar strains: EHV-1 and EHV-4. Both types can potentially lead to respiratory issues and abortion, but only EHV-1 has been associated with neurological disease. This disease can occur cyclically or sporadically and can affect horses of any age.
• When a horse is infected, the virus replicates within endothelial cells (cells lining the blood vessels) in the horse’s body, leading to a host of vascular issues. The clinical manifestations can vary considerably, with some horses only demonstrating mild clumsiness (ataxia), while others may develop swift, worsening paralysis.

Key Case Findings and Analysis

• The study revolves around two horses who developed neurological disease following EHV-1 infection. One of the horses also developed severe inflammation of the intestines (enteritis).
• The diagnosis was confirmed using specialized laboratory techniques, including testing with monoclonal antibodies and DNA analysis. The DNA analysis showed that the viruses from both horses were identical.
• The study reports of these horses developing symptoms such as lethargy, anorexia, fever, stiffness in the rear legs, and signs of depression. Ultimately, these symptoms worsened, progressing to ataxia, and both horses were ultimately euthanized.
• Post-mortem examination of both horses revealed several abnormal conditions, including signs of inflammation, congestion, edema, and necrotic lesions in various parts of the body, including the intestines.

Significance and Conclusion

• This research contributes another dimension to our understanding of EHV-1 by documenting spontaneous enteric lesions in adult horses, a first in veterinary literature.
• The detailed clinical progression and necropsy findings provide valuable insights that may assist in future diagnosis, treatment, and management of horses affected with EHV-1.