Hageman factor (factor XII) deficiency in marine mammals.

Hematologic and coagulation studies were conducted on Atlantic bottlenose dolphins and killer whales. Hematologic values were similar to those in man. These animals differed from other mammals in that the Hageman factor (factor XII) was absent and this absence caused marked prolongation of coagulation. Levels of factors VIII and V were high and those of VII and X were low compared with levels in man.