The Von Willebrand disease (VWD) is a common hereditary blood-clotting disorder, arising from a deficiency in the functioning of both platelets and blood clotting protein : the Von Willebrandfactor (vWF).  Due to this, normal hemostasis is disrupted, resulting in the fact that dogs suffering from VWD may bleed a longer period of time after injury, or can develop bleedings and bruises much faster.

In some cases the disease might be concealed for a long time and may be discovered only during f.e. surgery.  In other cases the disease could already by diagnosed when the dog is exchanging it’s baby teeth.

The von Willebrand factor (vWF) is a multimeric protein that is required for platelet adhesion and ‘closes’ a damaged blood vessel.  It is produced by platelets and cells surrounding the blood vessel and is construed from different smaller proteins.  VWD occurs when one of these proteins is defect. 

When a blood vessel ruptures and blood leaks, blood platelets are dispatched to attach themselves to the affected area in order to stop the bleeding.  While the platelets are doing their job, several blood thickening factors are activated that should lead to the productions of fibrin, the material of which scar tissue is construed, as to ensure a more permanent suture.