Disorder - Contact activation defect

Organ Systems Involved
Cardiovascular

Alternative disorders described within LIDA

Factor II deficiency; Factor VII deficiency; Factor VIII deficiency (haemophilia A); Factor IX deficiency (haemophilia B, Christmas disease); Factor X deficiency; Von Willebrand disease; Chediak-Higashi syndrome (platelet storage pool defect)

Alternative Names
Prekallikrein deficiency (Fletcher trait); HMWK deficiency (Fitzgerald trait); Factor XII deficiency (Hageman trait); Factor XI deficiency

Presenting Signs

Contact activation defect is a deficiency of one or more of the components involved in starting a blood clot. Specifically this includes deficiency in factor XII, prekallikrein (Fletcher factor), HMWK (high molecular weight kininogen) and/or factor XI. Deficiency in these factors alone rarely results in spontaneous bleeding tendencies, however if deficiencies in other clotting factors are present simultaneously, bleeding has been reported. Excessive bleeding may be more commonly seen after surgery (e.g. routine desexing, tooth extractions) or a trauma incident. Signs that may be seen include body cavity bleeding, large haematomas, bruising, or haemorrhage into joints resulting in lameness.

Breeds Affected
Siamese


Treatment

Medical: blood transfusions are usually the treatment of choice to control severe bleeding due to clotting factor deficiencies.

PubMed References
Contact activation defect

Contributor
Meichet Lee