Etiology:  Tyzzer’s disease is caused by Clostridium piliforme, a Gram-negative, intracellular, pleomorphic, spore-forming, motile bacterium.

Incidence:  The incidence of disease is low.  Clostridium piliforme has been reported to occasionally produce overt disease in hamsters.

Transmission:  Horizontal transmission occurs through ingestion of spores from contact with feces from infected hamsters.

Clinical Signs:  Infected hamsters exhibit hunched posture and rough hair coats with or without diarrhea.  Sudden death is a feature of the disease.

Pathology:  Gross pathologic lesions include enterocolitis with edema, lymphadenitis and rarely multifocal liver necrosis (arrow, A.).  Histologic lesions include chronic active hepatitis with coagulative necrosis (arrow, B.).

Diagnosis:  PCR of the cecum or feces can be used to reliably diagnose C. piliforme infection.  Demonstration of the organism in gut epithelium or hepatocytes by use of silver (black arrowhead, C.), staining techniques can also be used.  MFI or IFA can be used, but results are not always reliable.