[Optimized methods for measuring coagulation factors II, IV, VII and X in cats].

Since the single factor activity of the cat differed in part distinctly from humans (factor II: 94%, factor V: 500%, factor VII: 125%, factor X: 62%) the method had to be optimized, above all to exclude an influence of a reactive increased factor V-activity on the results of the other coagulation factors. Dilution series of cat pool plasma (CPP) (n = 50 cats) showed, that a commercial human placenta thromboplastin was more suitable as activating reagent than rabbit brain thromboplastin. Using the required sample predilution (1:40), measurements with the latter reagent were more precise when measured on the relation between the imprecision and the time interval between different CPP-dilution steps. Reference curves were prepared for CPP using the optimized method and human placenta thromboplastin (50 microliters 1:40 prediluted sample and 50 microliters deficient plasma were incubated at 37 degrees C for 1 minute, addition of 200 microliters Ca-thromboplastin) and reference ranges were calculated using the values of 57 cats (factor II: 74-126%, factor V: 42-184%, factor VII 56-150%, factor X: 65-143%).