Spontaneous disseminated cytomegalic inclusion disease in an ageing laboratory mouse

An untreated C57BL/6NCrlBR male mouse in a life-long longevity study, killed in extremis at 761 days of age, had mild focal necrotic hepatitis and extensive focal necrotic adrenalitis. Characteristic cytomegalic cells bearing intranuclear and cytoplasmic inclusions and cytoplasmic vacuoles were seen in necrotic areas. Scattered intranuclear inclusions were also seen in the reticulum cells of the spleen and acinar epithelium of the submaxillary glands. We believe this to be the first report of spontaneous disseminated cytomegalic inclusion disease in aged mice.