Equid herpesvirus 2-associated oral and esophageal ulceration in a foal.

This study discusses a case in which a 1-month-old racehorse developed mouth and esophagus sores due to infection with Equid herpesvirus 2 (EHV-2). The foal recovered after five days of specialized medical care, and was found to specifically have an EHV-2 infection, not EHV-1, -4, or -5.

Case Description

• The subject of the study is a 1-month-old Thoroughbred foal that presented with various symptoms like difficulty in swallowing, excessive saliva production, fever, pus-filled blisters on oral mucosal areas, and esophageal ulcers.

Diagnosis

• The diagnosis began with swabbing the ulcerated regions of the foal’s mouth and esophagus. The collected samples were able to produce Equid herpesvirus 2 (EHV-2) in virus isolation testing.
• A biopsy was taken from the esophageal lesion and examined through histopathology, where nuclear inclusions suggestive of herpesvirus were identified.
• Immunohistochemical staining procedures were performed using antibodies that are specific for EHV-2. The results revealed these antibodies present in the epithelial cells near the ulcer, while the distant mucosa tested negative.
• Further microscopic analysis of the biopsy showed particles indicative of a herpesvirus infection in the epithelial cells.

Treatment and Recovery

• The foal underwent a five-day course of supportive and gastroprotective therapy which led to its recovery, coupled with the healing of the esophageal ulcers.

Serological Testing and Immunohistochemistry

• Post-recovery, serological testing and further immunohistochemical analyses were done to determine the specific type of the virus. The results pinpointed the virus strain as EHV-2, not EHV-1, -4, or -5, confirming that the ulcers were a result of the EHV-2 infection.

Conclusion

• The study successfully demonstrated the association between EHV-2 and oral and esophageal ulcerations in foals, indicating the importance of considering EHV-2 as a potential diagnosis in such cases. Further studies could build upon these findings to explore treatment and prevention methods for EHV-2 related conditions in horses.