Definition of Von Willebrand Disease
Von Willebrand Disease (vWD) is the most common hereditary blood-clotting disorder in dogs. Dogs with vWD don’t have enough of a certain protein, called von Willebrand factor or factor VIII, in their blood. This protein is necessary for blood to clot, especially during the early stages of bleeding. Von Willebrand Disease is caused by genetic mutations that interfere with the production or function of the von Willebrand factor protein. Both males and females can pass this genetic mutation to their puppies. There are 3 different types of vWD, based on whether von Willebrand factor is reduced or entirely absent. Most dogs with vWD don’t have noticeable symptoms and are only diagnosed after surgery or an injury that causes bleeding. Dogs with severe vWD may bleed spontaneously from their nose or gums, have bloody stools and urine and bleed profusely during and after surgical procedures.