Von Willebrand's Disease (type I)Von Willebrand's disease is the most common inherited bleeding disorder in dogs and occurs when there is a lack of functional von Willebrand factor. Von Willebrand factor is needed for the normal adhesion of platelets, and therefore clotting of blood. There are 3 types of von Willebrand's disease. Type 1 is the most common form of the disease and usually causes mild to moderate symptoms. It has been reported in over 60 breeds, and is the type seen in the Pembroke Welsh Corgi.
Not all pups are affected equally when they have von Willebrand's disease, as the decrease in amount of von Willebrand factor can vary quite a lot. The genetic abnormality has been described as autosomal dominant with incomplete penetrance, which leads to the high variability in clinical expression. Different mutations have been reported. Some breeds are affected from birth, while others may not be affected until adulthood, or even middle age. DNA tests are available for some breeds, including the Pembroke, but some dogs that test "positive" may have severe disease, while others may never develop any bleeding tendency.
Signs of von Willebrand's disease are generally those of abnormal bleeding or prolonged periods of bleeding. If undiagnosed, affected dogs can suffer life-threatening haemorrhage at times of routine surgery or after a traumatic event. Treatment can often require blood or plasma transfusions.
Unfortunately, von Willebrand disease cannot be cured, but it can be managed.
There are certain drugs that should not be given to dogs with vWD, including NSAIDs (nonsteroidal anti-inflammatory drugs) and medications that involve any type of anticoagulant or anti-platelet activity. And there are also a few supplements that should not be given in high doses, including vitamins C and E and omega-3 fatty acids.
- DNA testing of all breeding animals performed prior to breeding - e.g. at 1 year of age.
- Measuring von Willebrand factor levels prior to surgery (e.g. neutering).