Von Willebrand disease is the most common inherited bleeding disorder in dogs, causing abnormal platelet function that leads to excessive bleeding from minor injuries, surgeries, and spontaneous hemorrhage.
Dogs with severe vWD experience bleeding episodes that cause pain, weakness, and potentially fatal blood loss. Spontaneous bleeding into joints causes the same intense pain as in humans with hemophilia. Bleeding into body cavities or the brain can be fatal. Minor injuries that healthy dogs would barely notice become significant welfare events requiring veterinary intervention. Surgical procedures - even routine ones like spaying or neutering - carry dramatically elevated risk without preparation. The hereditary nature of vWD means it is largely preventable through genetic testing in breeding programs, making every case in a breed where testing is available an example of preventable welfare harm.