- Spore-forming filamentous Gram negative intracellular pathogen
- Only grows in tissue culture or embryonated eggs
- Causes Tyzzer's disease - severe hepatic necrosis
- Sporadic disease in foals, calves, dogs, cats
- Foals under 6 weeks, found dead or comatose
- Incubation period up to 1 week
- Depression, anorexia, fever, jaundice, diarrhoea
- Hepatomegaly and necrosis on post mortem
- Diagnosis: Warthin-Starry silver impregnation technique demonstrates organisms in hepatocytes