“…It is the etiological agent of a rare, but frequently fatal septicaemia in neonatal foals also known as ''sleepy foal disease'' which is spread worldwide (Rycroft and Garside, 2000;Berthoud et al, 2002). Besides this acute form of disease, A. equuli can be associated with other types of infections in both foals and adult horses, such as abortion, enteritis, peritonitis, pleuropneumonia, pericarditis, periorchitis and arthritis (Webb et al, 1976;Dill et al, 1982;Al-Mashat and Taylor, 1986;Belknap et al, 1988;Peremans et al, 1991;Collins et al, 1994;Patterson-Kane et al, 2001). A. equuli has been subdivided in two different subspecies, designated A. equuli subsp.…”