Tyzzer's disease

Tyzzer's disease  is a contagious bacterial disease in rats and gerbils. It is caused by Clostridium piliforme, formerly known as Bacillus piliformis, a spore-forming bacterium.

It is transmitted horizontally through the fecal-oral route. Animals that carry the bacterium are usually asymptomatic, but a clinical syndrome may be seen in recently weaned rats.

Nonspecific signs such as anorexia, lethargy, emaciation, ruffled fur, or sudden death without clinical signs may be observed. Mucoid, bloody diarrhea may also be seen. On necropsy, animals may have megaileus. Many other organs, including liver, cecum, colon, and heart, can have characteristic pathologic lesions. Histopathologic observation of bacilli in target organs is diagnostic, and best obtained using a Warthin-Starry silver or Giemsa stain. There is no recommended treatment other than supportive care. Antibiotics effective against Clostridia spp. may be used.