The clotting disorder known as von Willebrand disease (vWD) is a relatively common and potentially lethal disease of dogs. Three general types of vWD (types I, II, and III) have been described based upon the specific genetic cause and level of deficiency in a protein known as von Willebrand factor (vWF), which plays an important role in blood coagulation. Dogs deficient in vWF protein are at risk of potentially life-threatening bleeding episodes when undergoing surgical procedures or as a result of traumatic injury. Therefore, when a relatively high frequency of Boykin spaniels was identified in the Paw Print Genetics (PPG) laboratory to carry a mutation in the VWF gene previously associated with vWDII in German shorthaired and wirehaired pointers (Kramer and colleagues), Boykin spaniel lovers and our team at Paw Print Genetics (PPG) were understandably concerned.
Concern turned to confusion as Boykins expected to be at risk for vWDII (based upon their genetic testing results) failed to show any signs of a clinical clotting disorder. In addition, results of additional blood tests looking at the product produced by the gene on several “at-risk” dogs showed no deficiency in vWF protein and no increase in blood clotting times. At that time ...