Congenital Afibrinogenemia

Inherited coagulation disorders have been diagnosed in many purebred dogs, mongrels, and cats. Hereditary fibrinogen deficiencies are autosomal incompletely dominant or recessive traits. Inherited hypofibrinogenemia has been detected in the Vizsla, Lhasa Apso, Saint Bernard, and Collie. Congenital afibrinogenemia, also called factor I deficiency and hypofibrinogenemia, is a relative lack of fibrinogen in the blood due to the defective fibrinogen synthesis. Fibrinogen is a glycoprotein that circulates in plasma and is synthesized by liver cells.

The primary physiological role of fibrinogen is in maintaining normal blood clotting. Hypofibrinogenemia is associated with mild bleeding episodes triggered by stress, trauma or surgery. It may be the result of a congenital blood abnormality or an acquired disorder. Deaths attributable to congenital afibrinogenemia are associated with postoperative and intracranial bleeding. Umbilical cord bleeding frequently provides an early alert to this hematologic-disease.1

To prevent excessive bleeding during surgical procedures, prophylactic treatment to raise fibrinogen levels is performed. Replacement is continued for 4-14 days following surgery, depending on the nature of the surgical procedure and time to complete healing. The treatment of choice for severe fibrinogen defects is intravenous transfusion with fresh or fresh-frozen plasma.3


  1. Sara J Israels, MD, FRCPC. Inherited Abnormalities of Fibrinogen
  2. Thomas Carlyle Jones, Ronald Duncan Hunt, Norval W. King. Veterinary Pathology
  3. Bernard F. Feldman, Joseph G. Zinkl, Nemi Chand Jain. Schalm's Veterinary Hematology