Tyzzer’s Disease in Laboratory Animals

Abstract

The spore-forming bacterium Clostridium piliforme, formerly known as Bacillus piliformis, is the source of Tyzzer's disease, an acute epizootic bacterial illness that is characterised by focal necrotic lesions on the liver and heart and segmental necrosis of the caecal mucosa. Young, well-fed animals, especially those given high-protein diets, are the animals most commonly affected by the disease. A Gram-negative, obligatory intracellular bacteria with varied shape in tissue sections, Clostridium piliforme. Production of exotoxin by bacteria leads to necrosis of intestinal epithelium. Bacteria can be returned to the lumen by being deposited there, or they can occasionally penetrate farther into the intestinal wall, where they can infect smooth muscle cells or enter the portal circulation. Bacteria from the portal vein may infect the heart and/or liver. Mortality is highest at weaning age in rabbits. Tyzzer's illness in mice can cause perianal discoloration, diarrhoea, and temporary appearances of being skinny and unclean. Additionally, sudden deaths without warning symptoms are possible. In rabbits there is watery diarrhoea leading to staining of hindquarter, lethargy and anorexia. Mortality occurred in weanling rabbits. In adult rabbits wasting disease is very common.