A 10-year-old alpaca with a history of anorexia, weight loss and diarrhoea was humanely destroyed and shown to have a multifocal necrotizing hepatitis, splenitis and colitis, as well as an ulcerative to diphtheroid ileitis. Immunohistochemical examination revealed Listeria monocytogenes antigen in the liver and ileum. In addition, L. monocytogenes and Listeria sp.-specific gene fragments were detected by the polymerase chain reaction. L. monocytogenes was isolated from liver and small intestine and Clostridium perfringens type A with beta(2) toxin was found in the small intestine. It is suggested that the infection with C. perfringens type A facilitated the systemic spread of L. monocytogenes.