Pathological Investigation of Salmonella Infection in Layer chicken at Nilphamari District of Bangladesh

Abstract

The research work was conducted during the period from July to December 2013 at Nilphamari district to investigate the pathology of Salmonella infection in layer birds. The histopathological studies were performed at the pathology laboratory of Hajee Mohammad Danesh Science and Technology Unuversity, Dinajpur and Bacteriological test was performed at the Laboratory of Nilsagor Agro Industries, Nilphamari. Salmonella organisms were isolated and identified from ovaries of dead layer birds and from inner content of laid eggs of different poultry farms. 38 ovarian swabs for bacteriology, visceral organs (liver, lung, spleen, egg follicles and intestine) of 38 dead birds for pathological study from 16 layer farms and 45 laid eggs (5 eggs/farm) from reported 9 Salmonella infected farms constituted samples of the study. Samples were subjected to isolation and identification of the causal agent followed by gross and histopathological study of the affected visceral organs. 17 of 38 ovarian swabs (44.7%) were Salmonella positive. The percentage of Salmonella gallinarum, Salmonella pullorum and paratyphoid causing Salmonella were 70.6%, 17.6% & 11.8%, respectively. About 53% livers of Salmonella affected birds were enlarged, congested, friable and bronze coloured with white necrotic foci. About 59% egg follicles were congested, hemorrhagic, discoloured with stalk formation and 70.6% intestines showed hemorrhagic to catarrhal enteritis. At histopathology, 76.5% livers were congested with formation of multifocal nodules and 82.4% egg follicles were congested with huge leukocytic infiltration. Infiltration of heterophils in intestinal mucosa was found in 47.1% cases. 4 Salmonella isolates were found from 9 laid egg samples (5 eggs content comprised as 1 sample) and isolation rate was 44.4% reporting transovarian transmission in poultry