Figure 1. Clinical symptoms found in Japanese macaques that developed severe thrombocytopenia.

The main clinical findings in the macaques that contracted the disease were reduced appetite, recumbency, facial pallor, hemorrhaging of the nasal mucosa and gums, subcutaneous bleeding, and brown-colored mucous and bloody stool. Necropsy of the dead macaques revealed hemorrhaging of all tissues, with particularly marked petechial hemorrhaging of the serosa and/or the mucous surface of the digestive tract and pulmonary hemorrhaging. (A) Facial pallor and hemorrhaging of the nasal mucosa, (B) bleeding from the alveolar ridge, (C) subcutaneous hemorrhage (chest), (D) subcutaneous hemorrhage (groin), (E) brown-colored mucous and bloody stool, (F) diffuse hemorrhaging of the lung, and (G) petechiae of the intestine. Photo courtesy of M.O., J.S., T.M.-N., A.W. and A.K.