Twelve horses were divided into three equal groups. Group I animals were inoculated orally with (3.7 X1012)CFU of a highly virulent strain of Salmonella typhimurium 3,;a_r cop§_n__hagen. Group 11 animals were inoculated orally with 2 doses of Salmonella and then challenged with a high dose. Group III horses, served as non - infected control. ‘
The main lesions were primarily confined to the digestive tract and were characterized by catarrhal enteritis. Pseudornembrane covered the mucosa of the ileum at the ileo — cecal Valve region.
Histopathological examination revealed marked rnononuclear cellular infiltration in the lamina propria and occasionally necrosis and edema in the mucosa and submucosa of the intestine.