Prekallikrein deficiency

From Dog

Prekallikrein deficiency (Fletcher Trait) is a rare genetic form of hemophilia.

Prekallikrein is a plasma protein that modulates the rate of activation of factors XI and factor XII in the intrinsic clotting system. In the absence of prekallikrein, factor XII is activated more slowly[1].

This disease is normally an asymptomatic condition, but post-operative bleeding may occur.

Prekallikrein deficiency has been reported in the Poodle. Combined prekallikrein deficiciency and factor XII deficiency has been reported in the Shar Pei[2], German Short-haired Pointer[3] and Shih Tzu[4].

Clinical signs are usually absent but hematuria[5], gastrointestinal hemorrhage[6] and excessive post-operative bleeding can occur.

Diagnosis is usually made coincidentally when coagulation screening tests are performed, which usually shows prolonged partial thromboplastin and activated clotting times[7].


  1. Cheville, NF (2006) Introduction to veterinary pathology. 3rd edition. Wiley-Blackwell Publications
  2. Cornell University
  3. Lisciandro, GR et al (2000) Contact factor deficiency in a German Shorthaired Pointer without clinical evidence of coagulopathy. J Vet Intern Med 14:308–310
  4. Okawa T et al (2011) Prekallikrein deficiency in a dog. J Vet Med Sci 73(1):107-111
  5. Chinn DR et al (1986) Prekallikrein deficiency in a dog. J Am Vet Med Assoc 188(1):69-71
  6. Otto, CM et al (1991) Factor XII and partial prekallikrein deficiencies in a dog with recurrent gastrointestinal hemorrhage. J Am Vet Med Assoc 198:129–131
  7. Merck Veterinary Manual