Hemophilia A in two related quarter horse colts.
Severe hemorrhagic diathesis caused by hemophilia A (factor VIII:C deficiency) was diagnosed in 2 related Quarter Horse colts. Clinical signs consisted of dyspnea and dysphagia attributable to cranial cervical hematoma in one colt and to intra-abdominal hemorrhage resulting in death of the second colt. Factor VIII:C deficiency, a defect of the intrinsic coagulation pathway, is suggested by results of coagulation studies--prolonged activated partial thromboplastin time, normal prothrombin time, and normal primary bleeding time. The diagnosis was confirmed by results of factor VIII:C assays. Hemophilia A is inherited as an X chromosome-linked trait.
D000818:Animals; D000941:Antigens / Q000032:analysis; D005169:Factor VIII / Q000032:analysis; D006467:Hemophilia A / Q000235:genetics / Q000662:veterinary*; D006734:Horse Diseases / Q000235:genetics*; D006736:Horses; D008297:Male; D010375:Pedigree
D000941:Antigens; D005169:Factor VIII