Clearance of cryoprecipitated factor VIII in canine hemophilia A.

Canine factor VIII was isolated by a cryoprecipitation method and injected into dogs with hemophilia A. Assays of factor VIII in the cryoprecipitate resulted in a range of 92 to 660% of the factor VIII level of normal dog plasma, with a mean of 266%. Half times of the cryoprecipitate in the hemophiliac dogs, as measured by the partial thromboplastin time (PTT) test, ranged from 7.7 to 32.3 hours, with a mean of 13.2 hours.