An etiopathological study on swine viral respiratory and reproductive diseases

Abstract

An etiopathological study was aimed to ascertain the prevalence of swine viral respiratory and reproductive diseases in pigs in and around Chennai, Tamil Nadu. Clinical samples consisted of blood, sera, nasal and rectal swabs were collected from two University Research Farms (URF) PGRIAS, Kattupakkam and ILFC, Madhavaram and two private farms located in and around Chennai. A total of 45 necropsies were conducted on pig carcasses during the study period consisting of 3 mummified fetuses, 17 still born fetuses, 5 pre- weaners, 8 weaners, 8 finishers and 4 adults. Representative tissue samples from the lungs, heart, liver, kidneys, spleen, lymph nodes, intestine and brain were collected on ice and in 10% neutral buffered formalin for histopathological, immunohistochemical and molecular studies. newlineImmunohistochemical studies were performed for the detection of viral antigen in tissue samples for PPV, PCV2 and CSF. In porcine parvovirus, immunolocalization of PPV antigen was observed in striated muscle cells of heart, lymphocytes and macrophages in spleen, macrophages of lymph nodes, alveolar epithelial cells of lungs, hepatocytes and renal tubular epithelial cells in fetal tissues. Porcine circovirus positive immunostaining of PCV2 antigen was observed in the macrophages of lymph nodes, lymphocytes and macrophages of spleen, alveolar epithelial cells of the lungs and hepatocytes of one piglet and 2 grower pig. In classical swine fever virus, positive immunostaining of antigen was observed in alveolar epithelium of lungs, tubular epithelial cells of kidneys and in hepatocytes of one finisher pig. newline