Etiology:  Enteritis occurs most frequently in 2 to 3 week-old hamsters and results primarily from colonization and proliferation of pathogenic bacteria.  The disease can also occur in older hamsters that experience a change in diet or with the administration of antibiotics which disrupt the normal gut flora.  Any enteric disease in hamsters will be complicated by proliferation of commensal flagellated enteric protozoa and amoeba.