Disseminated Intravascular Coagulation and Fibrinolysis

DIC&F is always secondary to a serious underlying illness or condition, such as: heat stroke, pancreatitis, septicemia/endotoxemia, neoplasia, trauma, obstetrical complications, tissue necrosis, or immune-mediated hemolysis. Therefore, history, clinical, and laboratory findings are particularly important in identifying precipitating factors and concurrent illness. Animals experiencing DIC&F may have clinical signs consistent with defects of primary and secondary hemostasis, as well as thrombosis. They are often simultaneously bleeding and clotting excessively. The CBC findings may include thrombocytopenia from consumption of platelets in the thrombi, anemia and hypoproteinemia from hemorrhage, schizocytes and keratocytes from fibrin strand injury to red cell membranes, and possibly an inflammatory leukogram depending on the underlying cause of DIC&F. Patients often experience organ failure, particularly renal failure from renal thromboembolism and shock.

The PT and PTT are initially shortened due to hypercoagulability, but later prolonged due to consumption of coagulation factors. Patients have usually reached the hypocoagulable stage when they are presented, unless the condition develops while already under veterinary care. A marked increase in fibrin/fibrinogen degradation products (FDPs) is often associated with excessive fibrinolysis, which can be useful in supporting the presence of DIC&F. However, excessive fibrinogenolysis and decreased clearance of FDPs (e.g. due to hepatic or renal disease) are situations where the increased FDPs are not associated with DIC&F. Fibrin D-dimers are fragments resulting from fibrinolysis that follows coagulation. Conditions associated with increased fibrinogenolysis are not detected by this test, making the D-dimer assay potentially more useful in diagnosing DIC&F. However, several problems have been identified with the various D-dimer assays that are currently available. Diagnosing the presence of DIC&F involves clinical evaluation, laboratory evaluation, and identifying the underlying serious condition that may have precipitated disturbed coagulation and fibrinolysis. Often the laboratory abnormalities described above are not all present, at any given point.