Von Willebrand Factor is an adhesive glycoprotein in the blood and is required for normal platelet binding at the sites of small blood vessel injuries. Also, it is a carrier protein for coagulation Factor VIII that is required for the blood to clot. A lack of this factor impairs platelet stickiness and clumping and can lead to excessive bleeding following an injury, due to the lack of clotting. This condition is called as Von Willebrand's Disease. This is a common hereditary blood clotting disorder in dogs, occurring with more frequency in some breeds, including German shepherds, Doberman pinschers, standard poodles, Shetland sheepdogs, and golden retrievers.
Some typical symptoms would include hemorrhage from mucosal surfaces, nosebleeds, blood in the feces or urine, bleeding gums, excessive bleeding from the vagina, bruising of skin, prolonged bleeding after surgery or trauma, and can be accompanied with blood loss anemia if there is prolonged bleeding.