Abstract
During the last few years a number of swine in the Missouri Agricultural Experiment Station† herd have died from hemorrhage, either spontaneous or as a result of minor wounds. All of the affected animals are closely related. It is evident that the blood-clotting mechanism is seriously defective, and a study was initiated in an attempt to classify the abnormality.
Bleeding Time. If determined by Duke's method 1 the bleeding time is within the normal range. As shown in Table I though, if an incision of any extent is made the bleeding time is prolonged indefinitely.
Coagulation Time. The procedure followed is essentially the same as the Lee-White 2 modification of Howell's method. The blood sample is taken from an ear vein, collected in cold paraffin coated tubes, and placed in an ice bath. The results reported in Table I show that the coagulation time was 5 times that of normal blood. The blood clots slowly, but after it forms it retracts in normal time.
According to the prevailing theory at least 4 components of the blood are intimately concerned with blood coagulation: (1) calcium; (2) prothrombin; (3) fibrinogen; (4) thromboplastin, which presumably is released from the platelets and other formed elements. Each one has been subjected to preliminary investigation.
Calcium Time. According to our observations the calcium time 3 is not less than the coagulation time, and the serum calcium was shown by analysis to be well within the normal range. Our data on calcium are omitted from the tabulations.
Fibrinogen Content. Oxalated plasma was diluted with isotonic saline and recalcified. The resulting fibrin was removed and determined quantitatively. The data shown in Table II indicate that the blood of defective animals contains slightly less fibrinogen than does that of normal controls, but the quantity is more than enough to form a normal clot.
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