Severe disease outbreaks of erysipelas in poultry flocks are caused by infectionwith the bacterium Erysipelothrix rhusiopathiae. This diseaseoccurs in a wide range of poultry, including turkey, broiler chicken, hen,goose, and pheasant flocks. Erysipelas usually follows an acute course in birds,in the form of sepsis. Infections with E. rhusiopathiae occurthrough damaged skin or mucous membranes. The symptoms that occur just beforedeath include unsteady locomotion and a lack of coordinated movement. A chronicform of bacterial infection primarily occurs in turkeys that have beenvaccinated against erysipelas, and, in addition to affecting the joints,endocarditis can occur. Usually, carcasses are in good condition and correctlymuscled, although ecchymosis might be visible in subcutaneous fat and thighmuscles, while internal organs become enlarged, such as the liver, spleen andkidneys. Histopathological tests indicate major vascular changes in theparenchymatous organs. Points of necrosis related to the infarctions of thelarge vessels are rarely observed, whereas spilled degenerative changes ofparenchymatous organs are more likely to be observed. Turkeys are the onlyspecies of poultry for which vaccines against erysipelas have been registered;however, this vaccination is also effective for other poultry. E.rhusiopathiae is mainly sensitive to penicillin, but also respondsto cephalosporins, tetracyclines, quinolines, clindamycin, erythromycin, andpiperacillin.