Question of the Day

A pattern of thrombocytopenia and increases in aPTT, PT, FDPs, and D-dimers suggests disseminated intravascular coagulation (DIC). DIC is a complex hemostatic defect arising secondary to other conditions, driven by unchecked inflammation and characterized by inappropriate activation of coagulation and consequent deposition of thrombi in the microvasculature.

Hypercoagulability hallmarks initial stages of DIC, whereas see global hypocoagulability, often with spontaneous hemorrhage, in later stages.

Lysis of fibrinogen, fibrin, or crosslinked fibrin generates FDPs, so elevated FDPs reflect excessive fibrinolysis, a later stage of the coagulation cascade. In contrast, D-dimers increase with both thrombin (early hemostasis) and plasmin (fibrinolysis) activation, so elevations indicate active clot formation and breakdown. See this diagram for a review of fibrinolysis.

Many diseases can result in DIC, but the more common conditions include: sepsis; advanced heartworm disease; immune-mediated hemolytic anemia; anaphylaxis; envenomation; heat stroke; and severe, fulminant pancreatitis. DIC is more common in dogs than in cats.

Zuku has a table of the four most important coagulation disorder patterns.

Images courtesy of Jen Mahon, DVM, DACVECC.
Diagram courtesy of JFDWolff.