Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, D-dimer, antithrombin III (AT III), protein C (PC), factor VII (F.VII), and factor VIII (F.VIII), as well as hematocrit (HCT), platelets number (PLT), total plasma protein (TP), and albumin (ALB), were studied on fifty-eight congestive heart failure (CHF) dogs with mitral valve disease (MVD) and fifty control dogs. All of variables of MVD group, except APTT, were significantly different (P < 0.5) from control group. The variables were also compared among functional classes of CHF dogs and control dogs. It was determined that the higher the functional class of CHF dogs was, the greater the levels of fibrinogen and D-dimer were, whereas the lesser the activities of AT III and PC were presented. Additionally, TP had linear correlation with fibrinogen, D-dimer, HCT, and PLT (r = 0.31, 0.30, 0.43, and 0.38, resp., P < 0.5). These findings suggested that fibrinogen and D-dimer were the factors predisposing hypercoagulability through an increase in blood viscosity. The hemorheological abnormalities would shift an overall hemostatic balance toward a more thrombotic state in CHF dogs with MVD.