Pathobiology of different chicken organs in septicemic deaths

Abstract

Septicemia in chicken is one of the main causes of death and leads to significant financial losses for the poultry farmers. There is very scarce information available in India on its pathology in chicken. Many bacterial pathogens are known to cause septicemia, either as primary agents or secondary agents, in association with other bacteria or viruses. The present study was conducted to explore the pathology in various organs of septicemic chickens. A total of 443 chicken carcasses with septicemic conditions from 71 different flocks were included in this study. The necropsy revealed 18.74%, 20.32%, and 60.95% of birds with mild, moderate and severe gross lesions respectively. Polyserositis with lesions such as hepatomegaly, splenomegaly and necrosis in the liver as well as generalized congestion were reported more frequently. On histopathological investigation, the more severe lesions were detected in the following organs: in decreasing order, the heart (66.20%), liver (64.79%), lungs (60.56%) and spleen (57.75%). Various microscopic lesions characteristic of septicemia have been reported, earlier ranging from acute inflammatory reactions such as vascular changes to chronic lesions such as granulomatous inflammation and fibrosis. Here, we made a first attempt to score gross and histopathological changes of septicemia in chicken and identified, described and documented the most common and distinctive septicemic lesions in different organs. This study was limited to 71 flocks of chicken suspected of septicemia due to limited logistics and time constraints. Hence detailed longitudinal study involving different types of birds with large sample size is required to elucidate the pathology of septicemia in chickens and to learn more about associated pathogens.