In this study, 20 neonatal diarrhoeic and 10 clinically healthy neonatal calves were used. Venous blood samples were collected from each animal to determine platelet numbers, pH, partial pressure of carbon dioxide (pCO(2)), partial pressure of oxygen (pO(2)), saturated oxygen (O(2)SAT), content of carbon dioxide (ctCO(2)), actual bicarbonate (HCO(3)act), standard bicarbonate (HCO(3)std), and actual base excess (actBE) of plasma. Plasma samples were collected from each animal for the measurement of prothrombin time (PT), thromboplastin time (aPTT), thrombin time (TT), and the concentrations of fibrinogen and cross- linked fibrinogen degradation products (D-dimer). Blood pH, HCO3act, HCO3std, actBE, ctCO2, and O2SAT values were significantly (P < 0.001) lower in diarrhoeic calves than in healthy controls. PT, aPTT, and TT values were prolonged (P < 0.005), and fibrinogen concentration increased (P < 0.001) significantly in calves with diarrhoea than in control calves, while D- dimer concentrations were negative in both diarrhoeic and control calves. The results suggest that a compensatory type of disseminated intravascular coagulation (DIC) develops in diarrhoeic calves.