Pathology of Spontaneously Occurring Salmonellosis in Commercial Broiler Chickens of Kashmir Valley

A study was conducted on spontaneous cases of Salmonellosis in different commercial broiler farms of Srinagar district and adjoining areas within the period from April 2008 to Oct 2009. A total of 42 outbreaks of Salmonellosis were recorded which included 24 outbreaks of fowl typhoid, 8 of paratyphoid, 3 of pullorum disease and 7 due to untypable serotypes. Clinical signs generally included ruffled feathers, huddling near the source of heat and light, anorexia, increased thirst, reluctance to move, pasted vent, diarrhoea, prostration, reduced growth rate and rarely lameness. The gross lesions comprised of hepatomegaly, bronze discoloration of liver, splenomegaly, congestion and necrotic foci on liver and spleen and pericarditis along with greyish white nodular lesions on heart. The lungs revealed varying degrees of congestion and haemorrhage. Bursa was atrophied and caeca revealed presence of caecal core. Histopathological alterations were observed principally in the liver, spleen, heart, kidney and bursa. Changes in liver and spleen comprised of congestion, haemorrhages, areas of necrosis, reticular endothelial hyperplasia along with mononuclear cell and heterophilic infiltration. Heart revealed congestion, focal and extensive infiltration of mononuclear cell and heterophils which occasionally resulted in atrophy, necrosis and replacement of muscles fibres by infiltrating cells. Depletion of lymphocytes was observed in both the spleen and bursa. Intestinal changes comprised of congestion of mucosal vessels along with marked hyperplasia of goblet cells and infiltration of heterophils and mononuclear cells in the lamina propria of villi.