Pathomorphological studies and detection of retroviral antigen by immunohistochemistry in ovine pulmonary adenomatosis

Abstract

In India, sheep rearing is very popular amongst the backward and weaker sections of the society. Of late, sheep rearing has taken a turn of entrepreneurship in large scale because of their feeding habits, ease in management and housing, early returns and increased technical awareness. Though sheep rearing is less expensive in terms of housing, feeding and management one should always concentrate on health aspect of these animals as they are very much prone to many infectious diseases including tumors. Although tumors are less common in domestic animals, with an exception of sheep in which, two important tumors namely ovine pulmonary adenomatosis (OPA) and enzootic nasal adenocarcinoma (ENA) are common and OPA alone constitutes 70% of all tumors in sheep. newlineOPA (Jaagsiekte) is a naturally occurring retro virus induced lung cancer in sheep, having long incubation period of 2-4 years and caused by Jaagsiekte sheep retro virus (JSRV) of the family Retroviridae. JSRV induces tumors via the oncogenic properties of its envelope that is necessary and sufficient to induce neoplastic transformation of alveolar (ATII) and bronchiolar (Clara) epithelial cells. Clinically, OPA is characterized by progressive a febrile respiratory illness with loss of weight (inspite of good appetite), tendency to lag behind the flock when moved and appear to have been chased ( driving sickness ), tachypnoea and characteristic moist rales due to accumulation of fluid in the air ways resulting in spasmodic coughing; pulmonary fluid discharging from the nostrils, dyspnoea and eventually death. newline newline