Factor VII Deficiency in Beagle Dog Plasma and its Use in the Assay of Human Factor VII

Abstract

DURING routine screening tests on a group of beagle dogs before a toxicological test, it was noted that several dogs showed a prolonging of the one-stage prothrombin time. Some of these dogs were found to be related (Fig. 1). The results of more detailed tests showed that intrinsic prothrombin activation was normal (Table 1) and that extrinsic prothrombin activation could be corrected by adding aliquots of normal human plasma or serum, normal dog plasma or serum, and Russell viper venom (Table 2). In addition, liver function tests were normal and the presence of an inhibitor was excluded (Table 3). Finally, factor VII activity assays, using congenitally deficient human plasma, confirmed that this factor specifically was reduced.