Genetic basis - caused by mutations in the F11 gene encoding coagulation Factor XI (FXI). Factor XI is a critical component of the intrinsic coagulation pathway. Documented mutations include a short interspersed nucleotide element (SINE) insertion in exon 7 of the F11 gene. Identified in several breeds, including Kerry Blue Terriers, English Springer Spaniels, Great Pyrenees, and Weimaraners. The exact inheritance pattern is not fully resolved but is generally considered autosomal recessive with incomplete penetrance.
Pathophysiology - Factor XI deficiency leads to reduced activity or levels of this clotting factor. Causes prolonged bleeding times after trauma or surgical procedures, usually with a delay of 12 to 24 hours post-injury. The intrinsic coagulation pathway is impaired, reducing effective blood clotting.
Complications - Life-threatening bleeding episodes following surgery or trauma. Delayed bleeding events (up to 4 days post-procedure). Potential need for plasma transfusions to control bleeding. Normal lifespan possible with proper management.
Why This Matters to Breeders and Vets - Factor XI deficiency may not manifest until after surgery or trauma, posing diagnostic challenges. Genetic testing helps identify carriers and affected dogs, preventing breeding of at-risk pairs. Knowing a dog's Factor XI status aids in planning surgeries and emergency treatments. It highlights the importance of coagulation screening for breeds predisposed to bleeding disorders.