VWF and hemophilia A: The bleeding disorder dogs (Group 1) consisted of 8 dogs with hereditary bleeding disorders: 2 Dobermans heterozygous for a VWF mutation with normal VWF:Ag and 1 Doberman deficient in VWF:Ag (VWD type 1), 1 Shetland sheepdog lacking detectable VWF (VWD type 3), 2 mixed breed dogs with Hemophilia A, and 2 dogs with Scott syndrome (n = 1 German shepherd, n = 1 Shepherd/Malinois mix).