Horse foetus lung: Bronchiolar epithelium positive for equine herpes virus 1 (EHV-1)
Animal: Horse, foetus, male.
History: The foetus aborted 1 month before expected parturition. It was one out of six aborted foetuses in a breeding centre. The mares in this breeding centre were not vaccinated against equine herpes virus.
Autopsy findings: The autopsy revealed general icteric discoloration. The lungs were oedematous with multifocal, white, necrotic processes and petechial haemorrhages. There were multifocal to confluent necrotic areas in the thymus. The spleen was enlarged with a few petechial haemorrhages in the capsule. Histology showed multifocal necroses, predominantly located to bronchioles, and intranuclear acidophilic inclusion bodies were found in the nuclei of bronchiolar epithelial cells. In the thymus and spleen there were necroses and cells with intranuclear acidophilic inclusion bodies in lymphoid follicles. In the liver there was leukocyte infiltration in the portal triads. Immunohistochemistry of lung, thymus, liver and spleen showed strong immunostaining for equine herpesvirus-1 (EHV-1).
Diagnosis: Abortion caused by EHV-1
Necropsy performed by : Helene Wisløff , National Veterinary Institute, Oslo.Photo by: Helene Wisløff