A subspecies serovar Choleraesuis outbreak in weaned piglets in Serbia: clinical signs, pathologic changes, and microbiologic features.

subspecies serovar Choleraesuis is rarely detected in Europe, but the clinical disease has been reported in wild boars. We describe here the clinical findings, pathologic changes, and microbiologic features of swine salmonellosis caused by serovar Choleraesuis in weaned piglets in Serbia. In April 2019, on a large farrow-to-finish pig farm, increased mortality was reported in weaned piglets, marked by lethargy, anorexia, pyrexia, and respiratory distress. Gross pathology revealed dermal cyanosis, mesenteric lymphadenopathy, splenomegaly, hepatomegaly, interstitial pneumonia, and colitis. By direct culturing of lung, liver, spleen, and lymph nodes, ser. Choleraesuis variant Kunzendorf was isolated after years of absence of the disease in pig farms in Europe. The source of this salmonellosis outbreak caused by ser. Choleraesuis remains unknown.