Experimental warfarin poisoning in the dog: Platelet function, coagulation and fibrinolysis

Experimental warfarin poisoning in dogs produced a profound haemostatic defect with depression in the levels of factors II, VII, IX and X and gross prolongation of the bleeding time. Surprisingly platelet function was unaltered suggesting that in the dog the intrinsic coagulation pathway plays an important part in the normal bleeding time. There was slight shortening of the euglobulin lysis time, but no other changes in the components of the fibrinolytic enzyme system. Rapid reversal of the clotting abnormality was produced by the intravenous injection of vitamin K 1.