An unusual clinical and pathological variant of malignant catarrhal fever in a white-tailed deer

A captive male white-tailed deer (Odocoileus virginianus) developed an acute illness over a 3-day period characterized predominantly by neurological, ocular and respiratory signs which were accompanied by prominent gross lesions of multiple organ systems. Histologically, a proliferative vasculitis consisting primarily of lymphocytic-lymphoblastic cellular infiltration was found in ocular, oral, respiratory, cardiac and neural tissues. The extensive nature of these infiltrations resulted in grossly apparent nodular foci in the lung, lymphoid tissue and myocardium which were suggestive of a lymphoproliferative disorder. This is contrasted to the more necrotizing nature of the vasculitis observed in other reported cases of malignant catarrhal fever in white-tailed deer. Although virus isolation was not attempted, serologic findings of antibodies to malignant catarrhal fever virus detected by indirect immunofluorescence and virus neutralization supported a diagnosis of malignant catarrhal fever in this deer.