Paratyphoid infection caused by Salmonella Typhimurium in a pigeon flock (Columbia livia) in Iran

Salmonellosis is well known as a severe problem of all bird species, as well as humans, which is considered as one of the most common infectious diseases in pigeons. In the present study, a homing pigeon flock was referred with non-specific clinical signs such as diarrhea, progressive weight loss, weakness, drooping wings associated with a 21.05% mortality rate. At necropsy, severe necrotic hemorrhagic enteritis was found together with severe dehydration and pectoral muscle atrophy. In order to investigate the possibility of Salmonella infection, bacterial examinations were performed on Brilliant Green (BG) agar, Xylose-lysine deoxycholate (XLD) agar, and Salmonella-Shigella (SS) agar plates. Besides, biochemical tests were conducted to confirm Salmonella identification. Moreover, tissue samples were taken for histopathological examination. The results of bacteriological examinations showed the presence of Salmonella Typhimurium through Salmonella colonies on the applicable media, Gram stain smears, and biochemical analysis. At histopathological studies, which consistent with the bacteriological findings, severe enterocyte necrosis, heterophil infiltration, and hemorrhage were observed in the intestinal mucosa. Moreover, there was vascular congestion together with focal necrosis and inflammation in the liver, kidney, and spleen. In conclusion, it seems that infection by S. Typhimurium is frequently occurring in pigeons by diarrhea and enteritis. Thus, it should be considered in relation to public health.