Pathological and Molecular Studies on Diagnosis of Infectious Bovine Abortions

Abstract

Bovine abortions have a multifactorial aetiology involving bacterial, viral, fungal and protozoan agents. In the present study, gross pathological, histopathological and polymerase chain reaction (PCR) technique(s) have been applied for diagnosis of infectious abortion in bovine. Histopathology was used as a reference technique to support the confirmation by PCR. Aborted bovine fetuses (n=31) of various gestational age and placenta (n=11) of aborted dam were or infectious diseases screened, which includes Neospora caninum, Brucella abortus, To/oplasma gondii and Infectious bovine rhinotracheitis virus. Gross lesions observed in aborted foetuses were serosanguineous fluid in the thoracic cavity, congestion of cerebrum, heart, liver and lungs. Lesions such as cerebral congestion with non-suppurative encephalitis, perivascular cuffing and Purkinje cell layer degeneration of brain, exfoliation of placental chorionic epithelium along with severe lymphomonocytic cell infiltrations were observed histopathologically. Eosinophilic intranuclear inclusions were observed in two placental tissues using routine H&E staining and special staining for inclusion bodies. PCR showed amplification of gene for the existence of N. caninum (1/31), Brucella (7/31) and BHV-1 (2/31) in the stomach content of aborted foetuses.