Malignant Catarrhal Fever in Bison, Acute and Chronic Cases

Abstract

Abstract. Acute malignant catarrhal fever (MCF) was diagnosed in 10 bison from 6 herds and ranging from 1 to 6 years of age. The pattern of clinical signs and morphologic lesions differed among bison. Combinations of corneal opacity, lacrimation, nasal discharge, depression, excess salivation, anorexia, diarrhea, melena, and hematuria were observed. Vasculitis characterized by lymphoid infiltrates in the adventia with variable extension into media and intima was found in multiple tissues in each animal. Fibrinoid vascular necrosis was rare. Ulceration in the alimentary tract was found in 9/10 bison, and ulceration or hemorrhage in the urinary bladder was found in 8/10 bison. Lymphoid infiltrates were present in 7 of 9 livers and 9 of 9 kidneys examined histologically. Hyperplasia of lymph nodes was observed in 5 bison. Chronic MCF was diagnosed in 1 bison with an 80-day course of illness that began with lacrimation, corneal opacity, mucoid nasal discharge, depression, and anorexia. These signs ceased after 15 days but circling and blindness developed on day 76. Chronic vascular lesions characterized by endothelial cell hypertrophy, intimal thickening, fragmentation of the internal elastic membrane, smooth muscle hypertrophy, and adventitial infiltrates of lymphocytes and plasma cells were found in many organs. The retinal arteries had chronic inflammation and acute transmural fibrinoid necrosis. The retinas were infarcted. Polymerase chain reaction technique for amplification of ovine herpesvirus 2 sequences was performed on formalin-fixed tissues, and viral sequences were detected in 1-7 tissues from each animal. These viral sequences were not found in tissues of 4 bison not affected by MCF.

An outbreak of malignant catarrhal fever in Murrah buffaloes in Minas Gerais, Brazil

“…In contrast, a fatal enteric clinical syndrome without vascular fibrinoid necrosis was observed in bisons (O'Toole et al 2002). Additionally, the lymphoid infiltrates in the liver and kidney, and lymphoreticular proliferation of lymph nodes was less severe in bisons than is usually seen in cattle and deer (Schultheiss et al 1998, Vikøren et al 2006.…”

Febre catarral maligna em bovinos no Rio Grande do Sul: transmissão experimental para bovinos e caracterização do agente etiológico

“…Isso sugere a possibilidade de que esses animais possam ser fonte da infecção horizontal ou vertical para outros membros do rebanho. Por outro lado, a infecção transplacentária de FCM já foi demonstrada em bovinos (Plowright et al 1972, O'Toole et al 1997) e bisões (Schultheiss et al 1998). Embora não se saiba se esses fetos iriam adoecer ou se tornar portadores, essa poderia ser uma explicação hipotética para a manutenção do vírus em determinadas propriedades por longos períodos.…”

Sheep associated malignant catarrhal fever: an emerging disease of bovids in India

“…Deer mostly die within 48 h of the appearance of the first symptoms and bison within three days [61]. In contrast, cattle usually survive a week or more post infection [33] although chronic cases have been described in cattle and bison [59,75]. Recovery from MCF is rare, nevertheless, there are reports of recovery in cattle that remained persistently infected [5,60].…”