The liver specifically shows mulifocal necrosis with inflammatory cell infiltration.
Splenic lesions consist of diffuse fibrinoid necrosis in the red pulp with lymphoid cell depletion.
Microscopically, the prominent sites of focal necrosis include the liver, lymphatic organs, kidneys, testes, and ovaries. The hepatocytes contain large eosinophilic intracytoplasmic inclusion bodies. Diffuse encephalitis, focal hemorrhage of the brain, and intravascular thrombi have also been observed. In the terminal stages, there is diffuse lymphoid necrosis and renal tubule necrosis. Generalized hemorrhage of organs accompanies the aforementioned lesions in fatal cases.