CpHV-2 infection in deer, on the contrary, is rarely encountered and usually produces mild and chronic clinical signs such as weight loss, dermal inflammation and alopecia. Peracute cases with sudden death and acute cases with hemorrhagic diarrhea are well documented and common in our experience of clinical investigation. In general, sika deer seem highly susceptible to OvHV-2. These deer species include sika deer ( Cervus nippon), white-tailed deer ( Odocoileus virginianus), Père David’s deer ( Elaphurus davidiansus), sambar deer ( Cervus unicolor), mule deer ( Odocoileus hemionus), moose ( Alces alces), red deer ( Cervus elaphus), red brocket deer ( Mazama americana), elk ( Cervus canadensis), rusa deer ( Cervus timorensis), Chinese water deer ( Hydropotes inermis) and axis deer ( Axis axis). Ī wide range of animals in the family Cervidae are susceptible to malignant catarrhal fever virus (MCFV) infections.
Lymphocytic vasculitis is a typical histological lesion of the disease. Characteristic lymphoid cell accumulation and infiltration in various tissues can be readily observed during microscopic investigation. Pathologically, heart, brain, lung and kidney are the most easily affected organs, although lesions may be found in any organ with different severities and frequencies. Oculonasal discharge could be an indication of the so-called head-and-eye form of MCF, whereas the intestinal tract form, the central nervous system (CNS) form and the cutaneous form of the disease are easily confused with other diseases. Dysentery or bloody diarrhea is common in most cases. In most cases, early clinical signs of the disease usually begin with high fever and depression, followed by catarrhal nasal discharges, mucosal ulcers and/or cloudy corneas. Upon infection, different clinical manifestations could be observed in the host depending on the affected organs. In addition to AlHV-1 and OvHV-2, caprine herpesvirus 2 (CpHV-2), ibex-MCFV, MCFV–white-tailed deer (WTD), and alcelaphine herpesvirus 2 (AlHV-2) have been reported to be pathogenic under natural conditions. In general, AIHV-1 causes MCF syndromes in ruminant wild animals in Africa and zoological animals worldwide, whereas OvHV-2 is more prevalent in domestic sheep, causing MCF in most regions of the world. Subclinically infected wildebeest and domestic sheep act as natural reservoirs, causing wildebeest-associated MCF (WA-MCF) and sheep-associated MCF (SA-MCF), respectively. Etiologically, alcelaphine herpesvirus 1 (AlHV-1) and ovine herpesvirus 2 (OvHV-2) are the most common causative agents. The disease is characterized as sporadic with low incidence and high mortality in bison, cattle, buffalo, deer and antelope. Malignant catarrhal fever (MCF) is a lymphoproliferative disease, caused by a group of closely related ruminant viruses within the genus Macavirus, in the subfamily Gammaherpesvirinae. Therefore, MCF should be put into a differential diagnostic list when similar disease occurs in sika deer herds. In addition, necrosis and inflammation in subcutaneous tissue surrounding a tendon was the reason for lameness. The disease was probably transmitted via aerosol infection. In summary, domestic goats were the reservoir of the CpHV-2, which is the causative agent of the outbreak of MCF in the three hinds. Etiologically, identical CpHV-2 specific DNA sequences were detected in peripheral blood lymphocyte (PBL) from the affected deer and reservoir goats. Severe lesions of hemorrhage, necrosis and infiltration of lymphoid cells could readily be observed in the lung, kidney, heart valves and subcutaneous tissue surrounding a tendon.
Affected deer developed clinical signs of high fever (41 ☌) followed by nasal discharge and lameness.
Here, we report a case of CpHV-2-associated acute MCF in a sika deer herd raised in an intensive management system distant to the reservoir goats. Caprine herpesvirus 2 (CpHV-2) infection usually induces chronic malignant catarrhal fever (MCF) in sika deer ( Cervus nippon), with the primary signs of weight loss, dermatitis and alopecia.
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