Abstract
Between May and June 1998, 17 farmed wild boars (Sus scrofa) on a farm in Kochi Prefecture died suddenly. Pathological and bacteriological examinations of 3 of the 17 animals confirmed an outbreak of septicemic erysipelas. Macroscopic examinations showed that cyanosis, enlarged lymph nodes, gastric and duodenal mucosal hemorrhage, and renal petechiae characterized the dead animals. Histological examination revealed thrombosis, histiocytosis, suppurative necrotic lymphadenitis, suppurative interstitial nephritis, and endoproliferative glomerulonephritis. Erysipelothrix rhusiopathiae serotype la was isolated from various organs including the lymph nodes. Although multidrug-resistant to other anitimicrobials, the isolates were highly suscentible to penicillins and were virulent enough to induce generalized erythema in swine.Immunostaining for E. rhusiopathiae serotype la produced postive reactions in macrophages and thrombi of various organs, especially the kidneys, spleen, and lymph nodes. Disinfection, penicillin administration, and vaccination eradicated the erysipelas endemic to the farm. The animals' high susceptibility to E. rhusiopathiae, their fierceness, the long fattening period (over two years), and the lack of legal meat-inspection obligations put serious obstacles in the way of preventing erysipelas in farmed Japanese wild boars.
