Encephalitis associated with
herpesvirus type 2 infection in a harbor porpoise. Cerebrum of harbor porpoise #2 infected with Phocoena phocoena herpesvirus type 2, an alphaherpesvirus. All tissue sections are stained with hematoxylin and eosin, and show mild freeze–thaw artifact. The encephalitis is characterized by an increased density of cells in the neuropil of the brain and the presence of dead neurons (arrowheads), which lack nuclei and have hypereosinophilic cytoplasm (A). In these areas, there are cuffs of mononuclear cells around blood vessels (B). Some of the affected neurons have eosinophilic intranuclear inclusion bodies, which are characteristic for herpesvirus infection (C).