Occurrence: Worldwide.
Species affected: All.
Age affected: All, usually young.
Causes: Salmonella typhimurium is a facultative anaerobe, with motile flagella, which produces endotoxins. There are many routes of transmission. It is difficult to eradicate as it can be transmitted by many wild biological vectors.
Effects: Young birds tremble (cry), whereas birds older than 1 month usually show subclinical disease. Young birds act cold, gasp and are anorectic. Watery diarrhoea, blindness, conjunctivitis, weakness and lameness can occur. There are often carriers without symptoms and there are risks for human health.