Corynebacterium pseudotuberculosis is the etiological agent of caseous lymphadenitis, a chronic infectious disease of sheep and goats. Despite the growing interest of this organism, little is known about the causality and effect of this organism on haematological and biochemical values. The purpose of this research, therefore was to determine haematological and serum biochemical features in mice inoculated with whole bacterium and exotoxin (PLD) extracted from C. pseudotuberculosis. The study was performed on apparently healthy mice of 2-3 weeks old (n = 64). The mice were divided equally into 3 groups; namely whole bacterium, exotoxin (PLD) and control group. Mice of whole bacterium group were exposed intraperitoneally to 1 mL of the inoculums containing 109 Colony-Forming Unit (CFU)/mL of live C. pseudotuberculosis. Exotoxin group were exposed intraperitoneally with a single dose of exotoxin (PLD) extracted from C. pseudotuberculosis. Mice served as a control group were challenged intraperitoneally to 1 mL of Phosphate-Buffered Saline (PBS), pH 7. Following post-infection, the mice were subjected for blood sample collection using cardiac puncture method for haematological and biochemical analysis. The results of this study revealed that there were significant decrease (p<0.05) in Hb, thrombocytes count and significant increase in WBC, neutrophils, monocytes counts in the infected group. Biochemically, there were highly significant increase (p<0.05) in the mean levels of CK, AST, ALP and ALT. The mean level of albumin in exotoxin group was significantly lower (p<0.05) compared to C. pseudotuberculosis and control groups while globulin level was significantly higher in C. pseuodotuberculosis group after 48 h. In serum electrolytes, mean level of potassium and phosphate were significantly (p<0.05) higher in infected groups compared to control group while there was no significant (p<0.05) difference in the levels of sodium, calcium and chloride. In conclusions, the present study of experimental nature showed that C. pseudotuberculosis and its exotoxin (PLD) cause disturbances in blood factors and electrolytes and pointed out that t hese haematological and biochemical alterations should be taken into account in the context of diagnosis and treatment of valuable infected hosts in order to prevent further consequences.