MEASUREMENTS OF THE ACTIVITY OF THE COAGU LATION-FACTOR-VIII-C, COAGULATION-FACTOR-IX, COAGULATION-FACTOR-XI AND COAGULATION-FACTOR-XII IN CATS

Using an optimized test, reference ranges were established for the act ivity of the coagulation factors VIII:C (72-124 %), IX (82-130 %), XI (69-134 %) and XII (51-242 %) in the cat (n = 58 cats, 2.5-97.5 % quan tile). Compared to a reference curve prepared by using a cat-pool plas ma (n = 50), the factor VIII:C activity in humans (commercial human re ference plasma) was 7.6 %, i.e. the factor VIII:C activity in cats was 13 fold higher than in humans. The values for the factors IX, XI and XII depended distinctly on the dilution step of the human plasma. The activity of the car in relation to humans was approximately 90 % (fact or IX), 170 % (factor XI) and 135 % (factor XII). Two clinically healt hy cats who were conspicuous pre-operative because of a distinctly pro longed, activated partial thromboplastin time showed a decreased facto r XII activity.